[gnome-builder] xml: update OVERVIEW.md

[Sébastien Lafargue <slafargue src gnome org>]

commit 7f293185d3f00945cef1a59984ee7127b372126c
Author: Sebastien Lafargue <slafargue gnome org>
Date:   Tue Feb 7 16:04:47 2017 +0100

    xml: update OVERVIEW.md

 plugins/xml-pack/OVERVIEW.md |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/plugins/xml-pack/OVERVIEW.md b/plugins/xml-pack/OVERVIEW.md
index 51cf2b5..8473e5d 100644
--- a/plugins/xml-pack/OVERVIEW.md
+++ b/plugins/xml-pack/OVERVIEW.md
@@ -79,3 +79,7 @@ Specifics processing:
 
 ## HTML and XML files
 
+Tag content is not shown.
+Comment content is shown on the same line as the comment node.
+CDATA content is not shown.
+Attributes are collected and shown on the same line as the tag node.