[devhelp] NEWS file: start to write news for 3.29.2

[Sébastien Wilmet <swilmet src gnome org>]

commit 3d8d7cb513602a7e57a6e3f868a50a178e3b6d4c
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Tue May 1 12:31:32 2018 +0200

    NEWS file: start to write news for 3.29.2

 NEWS |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
---
diff --git a/NEWS b/NEWS
index d1d2164..b9309dc 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,13 @@
+News in 3.29.2, 2018-xx-yy (not yet released)
+--------------------------
+* Decouple book selection from DhBook: remove DhBook "enabled" property,
+  introduce DhBookList base class, DhBookListSimple and DhBookListBuilder.
+* Allow custom search paths to load DhBooks: add DhBookListDirectory, remove
+  DhBookManager implementation.
+* DhProfile: add a DhBookList.
+* Listen to external changes to the "books-disabled" GSettings key.
+* Port other Devhelp classes to DhProfile and DhBookList.
+
 News in 3.29.1, 2018-04-15
 --------------------------
 * Switch build system from Autotools to Meson (and remove Autotools).