Maintenance for upcoming tutorials

As some of you are aware, I'm working on end-user documentation for Pyblish for it to reach a usable state by others. A *1.0 Alpha* if you will. This request covers some rounding off of corners for the documentation.

- [Overview](https://github.com/abstractfactory/pyblish/wiki/End-User-Overview)
- [Installation Tutorial](https://github.com/abstractfactory/pyblish/wiki/Installing)
- [Maya Tutorials](https://github.com/abstractfactory/pyblish-maya/wiki)

See description under each commit for details.