Updated mock release note and mock-index maxdepth

Mock release note contained rst syntax, that is not recognised by reno.
This commit trims excessive description, removes rst syntax not
understood by reno and marks inline markup in accordance with
doc contributors guide [1].
Also updates index.rst maxdepth to 2, to allow easier milestone
navigation from index page.

[1] http://docs.openstack.org/contributor-guide/rst-conv/inline-markups.html

Change-Id: I6368bd4b16d84e2a173e5dfba46124e41b394485

releasenotes/notes/enable-mocks-a156e7cc1b1d5066.yaml

@@ -1,24 +1,8 @@
 ---
 features:
   - Enable mocks in MuranoPL tests cases.
-    Those test cases are run with murano-test-tunner.
-    To enable mocks use the one of the *inject* YAQL functions
-    * `def inject(target, target_method, mock_object, mock_name)`
-    * `def inject(target, target_method, yaql_expr)`
-
-    Description
-    -----------
-
-     * *target* MuranoPL class name (namespaces can be used or full class name
-       in quotes) or MuranoPL object
-
-     * *target_method* Method name to mock in target
-
-     * *mock_object* Object, where mock definition is contained
-
-     * *mock_name* Name of method, where mock definition is contained
-
-     * *yaql_expr* YAQL expression, parameters are allowed
-     For more information, please follow the corresponding article in the
-     Murano developing applications guide.
+  - Added :command:`murano-test-tunner` command to run murano package tests.
+  - Introduced two YAQL *inject* functions to enable
+    mocks ``def inject(target, target_method, mock_object, mock_name)``
+    and ``def inject(target, target_method, yaql_expr)``.
 

releasenotes/source/index.rst

@@ -3,7 +3,7 @@
 ======================
 
 .. toctree::
-   :maxdepth: 1
+   :maxdepth: 2
 
    liberty
    unreleased