docs: Update Git URLs to GitHub

Per move to GitHub:

    https://lists.ozlabs.org/pipermail/patchwork/2015-October/001873.html

Signed-off-by: Stephen Finucane <stephen.finucane@intel.com>

Author: stephenfin

docs/index.md

@@ -20,7 +20,7 @@ of community projects.
 
 The latest version of Patchwork is available with git. To download:
 
-    $ git clone git://ozlabs.org/home/jk/git/patchwork
+    $ git clone git://github.com/getpatchwork/patchwork
 
 Patchwork is distributed under the [GNU General Public License].
 

mkdocs.yml

@@ -2,7 +2,7 @@ site_name: patchwork
 site_url: http://jk.ozlabs.org/projects/patchwork/
 site_description: patchwork - the web-based patch tracking system
 
-repo_url: git://ozlabs.org/home/jk/git/patchwork
+repo_url: git://github.com/getpatchwork/patchwork
 
 pages:
  - Home: 'index.md'