Documentation: various cosmetic changes

Documentation/contributing/index.rst

@@ -1,3 +1,4 @@
+============
 Contributing
 ============
 

Documentation/contributing/making-changes.rst

@@ -1,6 +1,7 @@
 .. include:: /substitutions.rst
 .. _making-changes:
 
+========================
 Making Changes Using Git
 ========================
 
@@ -65,7 +66,7 @@ Here's how to do it:
        $ git push
 
 Git Workflow With an Upstream Repository
-----------------------------------------
+========================================
 
 The main NuttX git repository is called an "upstream" repository - this is because it's the main source of truth, and
 its changes flow downstream to people who've forked that repository, like us.
@@ -160,7 +161,7 @@ maybe doing that several times. Then when everything works, I get my branch read
        $ git push
 
 Submitting Your Changes to NuttX
---------------------------------
+================================
 
   Pull requests let you tell others about changes you've pushed to a branch in a repository on GitHub. Once a pull
   request is opened, you can discuss and review the potential changes with collaborators and add follow-up commits
@@ -212,7 +213,7 @@ squash before submitting the Pull Request:
    1 through 6.
 
 How to Include the Suggestions on Your Pull Request?
-----------------------------------------------------
+====================================================
 
 If you submitted your first PR (Pull Request) and received some feedbacks
 to modify your commit, then probably you already modified it and created a
@@ -344,7 +345,7 @@ Now you can look at your PR at NuttX's github to confirm that
 this squashed commit is there.
 
 Git Resources
--------------
+=============
 
 * `Git Cheat Sheet (by GitHub) <https://github.github.com/training-kit/downloads/github-git-cheat-sheet.pdf>`_
 * `Git Book (online) <https://git-scm.com/book/en/v2>`_

Documentation/contributing/workflow.rst

@@ -1,5 +1,6 @@
 .. todo:: update when workflow is settled
 
+====================
 Development Workflow
 ====================