Publish draft 9.3 release notes

No links added yet.

Author: bmomjian

doc/src/sgml/filelist.sgml

@@ -159,6 +159,7 @@
 <!ENTITY sourcerepo SYSTEM "sourcerepo.sgml">
 
 <!ENTITY release    SYSTEM "release.sgml">
+<!ENTITY release-9.3    SYSTEM "release-9.3.sgml">
 <!ENTITY release-9.2    SYSTEM "release-9.2.sgml">
 <!ENTITY release-9.1    SYSTEM "release-9.1.sgml">
 <!ENTITY release-9.0    SYSTEM "release-9.0.sgml">

doc/src/sgml/release.sgml

@@ -78,6 +78,7 @@ can be created without links to the main documentation.  Don't use <xref>.
   The reason for splitting the release notes this way is so that appropriate
   subsets can easily be copied into back branches.
 -->
+&release-9.3;
 &release-9.2;
 &release-9.1;
 &release-9.0;