Update 2.13.6 release notes

Remove mention of "Rebase Always" which does not exist on 2.13; this
was copy and pasted from the commit message of a commit that had been
cherry-picked from master.

Fix misspelling of "submodule".

Change-Id: If61c1892c70cb876ebaa787a409ec486b0fa9f34
diff --git a/releases/2.13.md b/releases/2.13.md
index 3c99742..0bd4f68 100644
--- a/releases/2.13.md
+++ b/releases/2.13.md
@@ -478,7 +478,7 @@
 
 * Don't require Add Patch Set permission for submit by rebase.
 
-  When the submit strategy was Rebase Always or Rebase If Necessary and
+  When the submit strategy was Rebase If Necessary and
   a rebase was needed for the submit, the submit failed if the user
   didn't have the Add Patch Set permission. However for submitting a
   change the Submit permission alone should be sufficient.
@@ -531,7 +531,7 @@
 
     * Fix sorting of subscribed branches in submodule update.
 
-    * Fix handling of submdule config entries.
+    * Fix handling of submodule config entries.
 
     * Fix ordering of projects in submodule update.