Added syntax highlighting to intro.md
Updated intro.md 

- Rewrote a few sections
- Fixed code formatting
- Added external references
- Added better highlighting of important classes and keywords in various sections
Splitted first block into a new "documentary" section. Added "building and using" section
Merge branch 'master' of https://github.com/cH40z-Lord/Perspex into cH40z-Lord-master

Conflicts:
	Docs/intro.md
Merge branch 'cH40z-Lord-master'