Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Shortening headings and testing building of docs

    This patch shortens the headings and is used to test if the docs
    tool chain builds the right version.

    Change-Id: Ibc162be1b46ff787a90510c360881234391c5ba7
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 7c94c0e..8e2c2b4 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 7c94c0e8de23a090bf4530d573d689073f67b15f
+Subproject commit 8e2c2b42dff66d9896bfc5a8da8ee86cb18e8cb8