Case consistency for titles.

Author: pgasca

latest/ug/contribute/asciidoc-syntax.adoc

@@ -1,7 +1,7 @@
 [.topic]
 [#asciidoc-syntax]
 = AsciiDoc Syntax Reference
-:info_titleabbrev: AsciiDoc Syntax
+:info_titleabbrev: AsciiDoc syntax
 
 
 include::../attributes.txt[]
@@ -15,7 +15,7 @@ For advanced syntax, review the https://docs.asciidoctor.org/asciidoc/latest/[As
 It's important to get the link syntax right for the {aws} docs. Review how to <<insert-link>>. You cannot use Markdown syntax for links. 
 
 
-== Basic Formatting
+== Basic formatting
 
 [source,asciidoc]
 ----

latest/ug/contribute/edit-single-web.adoc

@@ -47,7 +47,7 @@ If you want to edit multiple pages from your web browser, see <<edit-web>>.
 
 You have created a pull request including the proposed changes.
 
-== Pull Request Overview
+== Pull request overview
 
 When you create a PR: