[metacity] doc: add info for 3.5 and 3.6 theme format versions

[Alberts Muktupāvels <muktupavels src gnome org>]

commit fd3a2404a16e17edbfe859decd11bc44acd647f9
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Sun Jan 18 16:17:54 2015 +0200

    doc: add info for 3.5 and 3.6 theme format versions

 doc/theme-format.txt |   12 ++++++++++++
 1 files changed, 12 insertions(+), 0 deletions(-)
---
diff --git a/doc/theme-format.txt b/doc/theme-format.txt
index 3ecfbbc..8c5d32d 100644
--- a/doc/theme-format.txt
+++ b/doc/theme-format.txt
@@ -22,6 +22,18 @@ This document has separate sections for each format version. You may
 want to read the document in reverse order, since the base features
 are discussed under version 1.
 
+New Features in Theme Format Version 3.6
+========================================
+
+Add new 'invisible_border' border in frame geometry. Used for resize
+cursor area.
+
+New Features in Theme Format Version 3.5
+========================================
+
+Add support for app-menu button in window decorations. This was only
+used by Mutter and here is only to support this Theme Format Version.
+
 New Features in Theme Format Version 3.4
 ========================================