Doc: minor improvements for our "Brief History" chapter.

Add a link to Joe Hellerstein's paper "Looking Back at Postgres",
which is quite an interesting take on the history of Postgres.

The reference to Appendix E was written when we were still keeping
the entire release-note history there, which we stopped doing some
years ago when the O(N^2) cost of that started to become apparent.
Instead, point to the release note archives on the website.
(This per suggestion from Daniel Gustafsson.)

In passing, move the "ports12" biblioentry to be in alphabetical
order within that section.

Discussion: https://postgr.es/m/3345678.1720071633@sss.pgh.pa.us

doc/src/sgml/biblio.sgml

@@ -230,27 +230,6 @@ ssimkovi@ag.or.at
   <bibliodiv>
    <title>Proceedings and Articles</title>
 
-   <biblioentry id="ports12">
-    <biblioset relation="article">
-     <title><ulink url="https://arxiv.org/pdf/1208.4179">Serializable Snapshot Isolation in PostgreSQL</ulink></title>
-     <authorgroup>
-      <author>
-       <firstname>D.</firstname>
-       <surname>Ports</surname>
-      </author>
-      <author>
-       <firstname>K.</firstname>
-       <surname>Grittner</surname>
-      </author>
-     </authorgroup>
-    </biblioset>
-    <confgroup>
-     <conftitle>VLDB Conference</conftitle>
-     <confdates>August 2012</confdates>
-     <address>Istanbul, Turkey</address>
-    </confgroup>
-   </biblioentry>
-
    <biblioentry id="berenson95">
     <biblioset relation="article">
      <title><ulink url="https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/tr-95-51.pdf">A Critique of ANSI SQL Isolation Levels</ulink></title>
@@ -288,6 +267,24 @@ ssimkovi@ag.or.at
     </confgroup>
    </biblioentry>
 
+   <biblioentry id="hell18">
+    <biblioset relation="article">
+     <title><ulink url="https://arxiv.org/pdf/1901.01973">Looking Back at Postgres</ulink></title>
+     <author>
+      <firstname>J.</firstname>
+      <surname>Hellerstein</surname>
+     </author>
+    </biblioset>
+    <biblioset relation="book">
+     <title>Making Databases Work</title>
+     <isbn>978-1-947487-19-2</isbn>
+     <publisher>
+      <publishername>Association for Computing Machinery and Morgan &amp; Claypool</publishername>
+     </publisher>
+     <pubdate>2018</pubdate>
+    </biblioset>
+   </biblioentry>
+
    <biblioentry id="olson93">
     <title>Partial indexing in POSTGRES: research project</title>
     <authorgroup>
@@ -328,6 +325,27 @@ ssimkovi@ag.or.at
    </biblioset>
    </biblioentry>
 
+   <biblioentry id="ports12">
+    <biblioset relation="article">
+     <title><ulink url="https://arxiv.org/pdf/1208.4179">Serializable Snapshot Isolation in PostgreSQL</ulink></title>
+     <authorgroup>
+      <author>
+       <firstname>D.</firstname>
+       <surname>Ports</surname>
+      </author>
+      <author>
+       <firstname>K.</firstname>
+       <surname>Grittner</surname>
+      </author>
+     </authorgroup>
+    </biblioset>
+    <confgroup>
+     <conftitle>VLDB Conference</conftitle>
+     <confdates>August 2012</confdates>
+     <address>Istanbul, Turkey</address>
+    </confgroup>
+   </biblioentry>
+
    <biblioentry id="rowe87">
    <biblioset relation="article">
     <title><ulink url="https://dsf.berkeley.edu/papers/ERL-M87-13.pdf">The <productname>POSTGRES</productname>

doc/src/sgml/history.sgml

@@ -17,6 +17,12 @@
   the most advanced open-source database available anywhere.
  </para>
 
+ <para>
+  Another take on the history presented here can be found in Dr. Joe
+  Hellerstein's paper <quote>Looking Back at Postgres</quote>
+  <xref linkend="hell18"/>.
+ </para>
+
  <sect2 id="history-berkeley">
   <title>The Berkeley <productname>POSTGRES</productname> Project</title>
 
@@ -215,8 +221,10 @@
   </para>
 
   <para>
-   Details about what has happened in <productname>PostgreSQL</productname> since
+   Details about what has happened in
-   then can be found in <xref linkend="release"/>.
+   each <productname>PostgreSQL</productname> release since then
+   can be found at
+   <ulink url="https://www.postgresql.org/docs/release/">https://www.postgresql.org/docs/release/</ulink>.
   </para>
  </sect2>
 </sect1>