users_guide: Update relnotes for 7.8.2

Signed-off-by: Austin Seipp <austin@well-typed.com>

docs/users_guide/7.8.2-notes.xml

+<?xml version="1.0" encoding="iso-8859-1"?>
+<sect1 id="release-7-8-2">
+  <title>Release notes for version 7.8.2</title>
+
+  <para>
+    The 7.8.2 release is a bugfix release. The changes relative to
+    7.8.1 are listed below.
+  </para>
+
+  <sect2>
+    <title>GHC</title>
+
+    <itemizedlist>
+       <listitem>
+          <para>
+            A bug which could cause GHC to reject programs which use a
+            type family on the right-hand side (RHS) of a type synonym
+            has been fixed.
+          </para>
+       </listitem>
+    </itemizedlist>
+  </sect2>
+</sect1>

docs/users_guide/intro.xml

@@ -308,6 +308,7 @@
 
 
 &relnotes1;
+&relnotes2;
 
 </chapter>
 

docs/users_guide/ug-ent.xml.in

@@ -4,6 +4,7 @@
 <!ENTITY license        SYSTEM "license.xml">
 <!ENTITY intro          SYSTEM "intro.xml" >
 <!ENTITY relnotes1      SYSTEM "7.8.1-notes.xml" >
+<!ENTITY relnotes2      SYSTEM "7.8.2-notes.xml" >
 <!ENTITY using          SYSTEM "using.xml" >
 <!ENTITY code-gens      SYSTEM "codegens.xml" >
 <!ENTITY runtime        SYSTEM "runtime_control.xml" >