Update Frontpage Documentation

[jquacinella]

The documentation on https://pythonhosted.org/Flask-Social/ is a little out of date. For example, there now needs to be a full_name field in the connection table, which is not presented there.

Also, it would be nice to indicate that the Twitter app thats created needs to allow for sign-ins (ok, thats kinda obvious I suppose) and that a callback URL needs to be specified. Maybe give some snap shots of the application settings for each provider?

[jquacinella]

Something I just noticed as well: removing links to an OAuth account does not work unless you have the middleware that is shown in flask-social-example. Maybe this should be built into the library? Either way, a mention of this on the frontpage of Flask-Social would be awesome. Thanks!

[eriktaubeneck]

We've had the discussion about the middleware recently, and I believe we agreed adding something to the documentation would be sufficient. Would you like to submit a PR?

[jquacinella]

#46

[jquacinella]

I never did a Pull Request before, I hope it works. I added the middleware (from Matt Upstate) and changed the HTML form to use it correctly.

[eriktaubeneck]

Merged #46