Adds local toc sections

* Some of our chapters are pretty long and this should make it much
  easier for a user to find what they're looking for and jumping
  to it.  It's easier to read the section toc at the top of the
  chapter, than it is to read it in the sidebar.

docs/codebase.rst

@@ -4,6 +4,10 @@
  Codebase Documentation
 ========================
 
+.. contents:: Sections
+   :local:
+
+
 This chapter covers the libraries that GNU MediaGoblin uses as well as
 various recipes for getting things done.
 

docs/contributinghowto.rst

@@ -4,6 +4,10 @@
  Contributing HOWTO
 ====================
 
+.. contents:: Sections
+   :local:
+
+
 .. _join-the-community-section:
 
 Join the community!

docs/designdecisions.rst

@@ -4,6 +4,10 @@
  Design Decisions
 ==================
 
+.. contents:: Sections
+   :local:
+
+
 This chapter talks a bit about design decisions.
 
 

docs/git.rst

@@ -2,6 +2,10 @@
  Git, Cloning and Patches
 ==========================
 
+.. contents:: Sections
+   :local:
+
+
 GNU MediaGoblin uses git for all our version control and we have the
 repositories hosted on `Gitorious <http://gitorious.org/>`_.  We have
 two repositories:

docs/hackinghowto.rst

@@ -4,6 +4,10 @@
  Hacking HOWTO
 ===============
 
+.. contents:: Sections
+   :local:
+
+
 So you want to hack on GNU MediaGoblin?
 =======================================