doc: Fix <synopsis> in <term> markup

Although the DTD technically allows this, the resulting HTML is invalid
because it puts block elements inside inline elements.  DocBook 5.0 also
doesn't allow it anymore, so it's fair to assume that this was never
really intended to work.  Replace <synopsis> with <literal>, which is
the markup used elsewhere in the documentation in similar cases.

doc/src/sgml/textsearch.sgml

@@ -859,10 +859,7 @@ SELECT plainto_tsquery('english', 'The Fat & Rats:C');
       </indexterm>
 
       <term>
-<synopsis>
-ts_rank(<optional> <replaceable class="PARAMETER">weights</replaceable> <type>float4[]</>, </optional> <replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>,
-        <replaceable class="PARAMETER">query</replaceable> <type>tsquery</> <optional>, <replaceable class="PARAMETER">normalization</replaceable> <type>integer</> </optional>) returns <type>float4</>
-</synopsis>
+       <literal>ts_rank(<optional> <replaceable class="PARAMETER">weights</replaceable> <type>float4[]</>, </optional> <replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>, <replaceable class="PARAMETER">query</replaceable> <type>tsquery</> <optional>, <replaceable class="PARAMETER">normalization</replaceable> <type>integer</> </optional>) returns <type>float4</></literal>
       </term>
 
       <listitem>
@@ -879,10 +876,7 @@ ts_rank(<optional> <replaceable class="PARAMETER">weights</replaceable> <type>fl
       </indexterm>
 
       <term>
-<synopsis>
-ts_rank_cd(<optional> <replaceable class="PARAMETER">weights</replaceable> <type>float4[]</>, </optional> <replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>,
-           <replaceable class="PARAMETER">query</replaceable> <type>tsquery</> <optional>, <replaceable class="PARAMETER">normalization</replaceable> <type>integer</> </optional>) returns <type>float4</>
-</synopsis>
+       <literal>ts_rank_cd(<optional> <replaceable class="PARAMETER">weights</replaceable> <type>float4[]</>, </optional> <replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>, <replaceable class="PARAMETER">query</replaceable> <type>tsquery</> <optional>, <replaceable class="PARAMETER">normalization</replaceable> <type>integer</> </optional>) returns <type>float4</></literal>
       </term>
 
       <listitem>
@@ -1226,9 +1220,7 @@ FROM (SELECT id, body, q, ts_rank_cd(ti, q) AS rank
      </indexterm>
 
      <term>
-<synopsis>
-<type>tsvector</> || <type>tsvector</>
-</synopsis>
+      <literal><type>tsvector</> || <type>tsvector</></literal>
      </term>
 
      <listitem>
@@ -1267,9 +1259,7 @@ FROM (SELECT id, body, q, ts_rank_cd(ti, q) AS rank
      </indexterm>
 
      <term>
-<synopsis>
-setweight(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>, <replaceable class="PARAMETER">weight</replaceable> <type>"char"</>) returns <type>tsvector</>
-</synopsis>
+      <literal>setweight(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>, <replaceable class="PARAMETER">weight</replaceable> <type>"char"</>) returns <type>tsvector</></literal>
      </term>
 
      <listitem>
@@ -1297,9 +1287,7 @@ setweight(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>,
      </indexterm>
 
      <term>
-<synopsis>
-length(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) returns <type>integer</>
-</synopsis>
+      <literal>length(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) returns <type>integer</></literal>
      </term>
 
      <listitem>
@@ -1316,9 +1304,7 @@ length(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) re
      </indexterm>
 
      <term>
-<synopsis>
-strip(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) returns <type>tsvector</>
-</synopsis>
+      <literal>strip(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) returns <type>tsvector</></literal>
      </term>
 
      <listitem>
@@ -1352,9 +1338,7 @@ strip(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) ret
     <varlistentry>
 
      <term>
-<synopsis>
-<type>tsquery</> &amp;&amp; <type>tsquery</>
-</synopsis>
+      <literal><type>tsquery</> &amp;&amp; <type>tsquery</></literal>
      </term>
 
      <listitem>
@@ -1368,9 +1352,7 @@ strip(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) ret
     <varlistentry>
 
      <term>
-<synopsis>
-<type>tsquery</> || <type>tsquery</>
-</synopsis>
+      <literal><type>tsquery</> || <type>tsquery</></literal>
      </term>
 
      <listitem>
@@ -1384,9 +1366,7 @@ strip(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) ret
     <varlistentry>
 
      <term>
-<synopsis>
-!! <type>tsquery</>
-</synopsis>
+      <literal>!! <type>tsquery</></literal>
      </term>
 
      <listitem>
@@ -1404,9 +1384,7 @@ strip(<replaceable class="PARAMETER">vector</replaceable> <type>tsvector</>) ret
      </indexterm>
 
      <term>
-<synopsis>
-numnode(<replaceable class="PARAMETER">query</replaceable> <type>tsquery</>) returns <type>integer</>
-</synopsis>
+      <literal>numnode(<replaceable class="PARAMETER">query</replaceable> <type>tsquery</>) returns <type>integer</></literal>
      </term>
 
      <listitem>
@@ -1440,9 +1418,7 @@ SELECT numnode('foo &amp; bar'::tsquery);
      </indexterm>
 
      <term>
-<synopsis>
-querytree(<replaceable class="PARAMETER">query</replaceable> <type>tsquery</>) returns <type>text</>
-</synopsis>
+      <literal>querytree(<replaceable class="PARAMETER">query</replaceable> <type>tsquery</>) returns <type>text</></literal>
      </term>
 
      <listitem>
@@ -1495,9 +1471,7 @@ SELECT querytree(to_tsquery('!defined'));
      <varlistentry>
 
       <term>
-<synopsis>
-ts_rewrite (<replaceable class="PARAMETER">query</replaceable> <type>tsquery</>, <replaceable class="PARAMETER">target</replaceable> <type>tsquery</>, <replaceable class="PARAMETER">substitute</replaceable> <type>tsquery</>) returns <type>tsquery</>
-</synopsis>
+       <literal>ts_rewrite (<replaceable class="PARAMETER">query</replaceable> <type>tsquery</>, <replaceable class="PARAMETER">target</replaceable> <type>tsquery</>, <replaceable class="PARAMETER">substitute</replaceable> <type>tsquery</>) returns <type>tsquery</></literal>
       </term>
 
       <listitem>
@@ -1521,9 +1495,7 @@ SELECT ts_rewrite('a &amp; b'::tsquery, 'a'::tsquery, 'c'::tsquery);
      <varlistentry>
 
       <term>
-<synopsis>
-ts_rewrite (<replaceable class="PARAMETER">query</> <type>tsquery</>, <replaceable class="PARAMETER">select</> <type>text</>) returns <type>tsquery</>
-</synopsis>
+       <literal>ts_rewrite (<replaceable class="PARAMETER">query</> <type>tsquery</>, <replaceable class="PARAMETER">select</> <type>text</>) returns <type>tsquery</></literal>
       </term>
 
       <listitem>
@@ -3239,9 +3211,7 @@ SELECT plainto_tsquery('supernovae stars');
      </indexterm>
 
      <term>
-<synopsis>
-CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> USING gist(<replaceable>column</replaceable>);
-</synopsis>
+      <literal>CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> USING gist(<replaceable>column</replaceable>);</literal>
      </term>
 
      <listitem>
@@ -3262,9 +3232,7 @@ CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable>
      </indexterm>
 
      <term>
-<synopsis>
-CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> USING gin(<replaceable>column</replaceable>);
-</synopsis>
+      <literal>CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable> USING gin(<replaceable>column</replaceable>);</literal>
      </term>
 
      <listitem>
@@ -3414,7 +3382,7 @@ CREATE INDEX <replaceable>name</replaceable> ON <replaceable>table</replaceable>
 
   <variablelist>
    <varlistentry>
-    <term><synopsis>\dF<optional>+</optional> <optional>PATTERN</optional></synopsis></term>
+    <term><literal>\dF<optional>+</optional> <optional>PATTERN</optional></literal></term>
     <listitem>
      <para>
       List text search configurations (add <literal>+</> for more detail).
@@ -3455,7 +3423,7 @@ Parser: "pg_catalog.default"
    </varlistentry>
 
    <varlistentry>
-    <term><synopsis>\dFd<optional>+</optional> <optional>PATTERN</optional></synopsis></term>
+    <term><literal>\dFd<optional>+</optional> <optional>PATTERN</optional></literal></term>
     <listitem>
      <para>
       List text search dictionaries (add <literal>+</> for more detail).
@@ -3486,7 +3454,7 @@ Parser: "pg_catalog.default"
    </varlistentry>
 
    <varlistentry>
-   <term><synopsis>\dFp<optional>+</optional> <optional>PATTERN</optional></synopsis></term>
+   <term><literal>\dFp<optional>+</optional> <optional>PATTERN</optional></literal></term>
     <listitem>
      <para>
       List text search parsers (add <literal>+</> for more detail).
@@ -3539,7 +3507,7 @@ Parser: "pg_catalog.default"
    </varlistentry>
 
    <varlistentry>
-   <term><synopsis>\dFt<optional>+</optional> <optional>PATTERN</optional></synopsis></term>
+   <term><literal>\dFt<optional>+</optional> <optional>PATTERN</optional></literal></term>
     <listitem>
      <para>
       List text search templates (add <literal>+</> for more detail).