Fix a couple more places in docs for pg_lsn change

Also, revert Unicode linestyle to ASCII.

Reported-by: Japin Li <japinli@hotmail.com>
Discussion: https://postgr.es/m/ME0P300MB04453A39931F95805C4205A8B64FA@ME0P300MB0445.AUSP300.PROD.OUTLOOK.COM

doc/src/sgml/datatype.sgml

@@ -5121,7 +5121,7 @@ WHERE ...
     <literal>+(pg_lsn,numeric)</literal> and
     <literal>-(pg_lsn,numeric)</literal> operators, respectively. Note that
     the calculated LSN should be in the range of <type>pg_lsn</type> type,
-    i.e., between <literal>0/0</literal> and
+    i.e., between <literal>0/00000000</literal> and
     <literal>FFFFFFFF/FFFFFFFF</literal>.
    </para>
   </sect1>

doc/src/sgml/func.sgml

@@ -28521,7 +28521,7 @@ acl      | {postgres=arwdDxtm/postgres,foo=r/postgres}
         Returns information about the progress of the WAL summarizer. If the
         WAL summarizer has never run since the instance was started, then
         <literal>summarized_tli</literal> and <literal>summarized_lsn</literal>
-        will be <literal>0</literal> and <literal>0/0</literal> respectively;
+        will be <literal>0</literal> and <literal>0/00000000</literal> respectively;
         otherwise, they will be the TLI and ending LSN of the last WAL summary
         file written to disk. If the WAL summarizer is currently running,
         <literal>pending_lsn</literal> will be the ending LSN of the last

doc/src/sgml/pageinspect.sgml

@@ -741,9 +741,9 @@ test=# SELECT first_tid, nbytes, tids[0:5] AS some_tids
       For example:
 <screen>
 test=# SELECT * FROM gist_page_opaque_info(get_raw_page('test_gist_idx', 2));
-    lsn     │    nsn     │ rightlink │ flags  
-────────────┼────────────┼───────────┼────────
- 0/0B5FE088 │ 0/00000000 │         1 │ {leaf}
+    lsn     |    nsn     | rightlink | flags  
+------------+------------+-----------+--------
+ 0/0B5FE088 | 0/00000000 |         1 | {leaf}
 (1 row)
 </screen>
      </para>