Tidy up tripleo docs merge contributor & developer guides

This merges the developer guide and contributor guide in index

Change-Id: I8743c5930aa46cde2735943b87e047e25ff169af
Related-Bug: #1804642

doc/source/developer/index.rst

@@ -9,3 +9,4 @@ Documentation of developer-specific options in |project|.
    tht_walkthrough/tht_walkthrough
    release
    mistral_workflows/00-index
+   ../upgrade/developer/upgrades/upgrades

doc/source/index.rst

@@ -4,8 +4,7 @@ Welcome to |project| documentation
 TripleO is a project aimed at installing, upgrading and operating OpenStack
 clouds using OpenStack's own cloud facilities as the foundation - building on
 Nova, Ironic, Neutron and Heat to automate cloud management at datacenter
-scale.
-
+scale
 
 Contributor Guide
 -----------------
@@ -15,6 +14,7 @@ Contributor Guide
   :includehidden:
 
   contributor/index
+  developer/index
 
 Install Guide
 -------------
@@ -34,15 +34,6 @@ Upgrades/Updates/FFWD-Upgrade
 
   upgrade/index
 
-Developer Guide
----------------
-
-.. toctree::
-  :maxdepth: 3
-  :includehidden:
-
-  developer/index
-
 Documentation Conventions
 =========================
 

doc/source/upgrade/developer/upgrades/upgrades.rst

@@ -1,5 +1,5 @@
-Developer Docs
-==============
+Upgrades Development
+====================
 
 This section is intended to give a better understanding of the upgrade/update
 process in TripleO. As well as a walkthrough for developers on the way upgrade