Update README.md

Updated the Fedora instructions
Update README.md
All commands should accept $2 the root directory properly.

Fixed #24. run-* commands should append $ROOT, even if it's $PWD=='.'
Fixed #25. develop should take $ROOT when sourcing.
Fixed #26. remove trailing slash.
Merge branch 'master' of https://github.com/yeukhon/minion into yeukhon-master

Conflicts:
	setup.sh
Allow -p and -a option for run-backend and run-frontend.

Fixed #28. I also make -x option, which specifies the root directory (instead
of the original implicit $2 being the positional argument for the root directory path)

Conflicts:

	setup.sh
Allow command to be in the first position rather than the last. See #28.

The problem with getopts is that it cannot handle non-optional args before
optional arguments apepar.

So ./setup.sh run-backend -x ./ will not work unless we shift $1. This patch makes
the code a bit cleaner.
Added gitignore.
Initialized sphinx docs.
Wrote the introduction page and quickstart page.
Wrote plugins and contribute page.
Added resources and fix cross-doc reference.
Added requirement file for pip to install sphinx and theme.
Fixed unknown directive code to code-block.
Added a persona section explaining how to sign up an account.
Added a user guide and updated various minion doc.
Added a doc to guide people to install plugin for the first time.
Getting started with Minion.
Added a guide to use setup.sh
Added a guide to use the frontend (and images).
Added a guide to install backend and frontend individually.