Pdpinch/documentation updates

WIP. Not ready to merge yet. 

@cgee or @bdero can you review the installation instructions, esp. part 3:

https://github.com/mitodl/edx-sga/blob/pdpinch/documentation-updates/README.rst#installation
I mentioned all the AWS settings explicitly. 

On Oct 24, 2014, at 10:07 AM, Carson Gee <notifications@github.com> wrote:

> In README.rst:
> 
> >        .. code:: sh
> >  
> > -          sudo su edxapp
> > -          paver devstack studio
> > +          del DEFAULT_FILE_STORAGE
> > +          MEDIA_ROOT = "/edx/var/edxapp/uploads"
> > +   
> > +   2. Use S3 storage (default)
> > +   
> > +      - TBD directions for changing S3 settings
> To enable S3 storage, set the following values in your lms.auth.json file, or preferably in your additional yaml overrides in your edx/configuration setup.
> 
>     "AWS_ACCESS_KEY_ID": "your bucket AWS access key ID",
>     "AWS_SECRET_ACCESS_KEY": "Your bucket AWS access key secret",
>     "AWS_STORAGE_BUCKET_NAME": "Your upload bucket name",
> —
> Reply to this email directly or view it on GitHub.
>