Clean up and standardize landing pages

doc index.rst:
1. Correct heading levels (impacting side nav and correct rendering of content)
2. Remove "Indices and Tables" section: genindex page not used, move search link to intro sentence.

spec instructions.rst:
1. Update page title to be consistent w/ incoming link text (so that link with text "How to submit a spec" goes to a page titled "Submit a Spec")
2. Add section header to first list on page

Change-Id: Ic3071bcf1c8d152c68d6735f08bb97e768aa944f
Signed-off-by: Kristal Dale <kristal.dale@intel.com>

doc/source/index.rst

@@ -4,10 +4,15 @@
 OpenStack StarlingX Project Plans
 =================================
 
-Specifications
-==============
+Learn more about StarlingX project specifications for specific relseases
+and the process to submit a specification.
 
-Here you can find the specs, and spec template, for each release:
+Specification content can be searched using the :ref:`search page <search>`.
+
+Specifications
+--------------
+
+Here you can find the specs and spec template for each release:
 
 .. toctree::
    :glob:
@@ -16,7 +21,7 @@ Here you can find the specs, and spec template, for each release:
    specs/2019.03/index
 
 Process
-=======
+-------
 
 Documentation for stx-specs process:
 
@@ -27,8 +32,3 @@ Documentation for stx-specs process:
 
 For more details, look at spec template for the specific release, and see the
 wiki page on Blueprints: https://wiki.openstack.org/wiki/Blueprints
-
-Indices and tables
-==================
-
-* :ref:`search`

specs/instructions.rst

@@ -10,9 +10,12 @@
 
 .. _instructions:
 
-============
+=============
+Submit a Spec
+=============
+
 Instructions
-============
+------------
 
 - Use STX_Example_Spec.rst under the ``approved`` subfolder of the applicable
   release as the basis of your specification.