Update 00-intro.md
Consistent use of ###### Note: blocks

This should help with styling and also makes it consistent with the MD for the TF app
Removed the module from quick Controller example

Makes the code way more simple (no unexplained module) as well as demonstrates the global `ng-app`.
Updated scope link to more relevent

The general CS scope link was way complicated and abstract, swapped it out for (ms) JavaScript docs about Scope of variables; seems more useful and less confusing.
Using function declaration for controller example

Much more simple as we haven't introduced module and dependency injection yet, also added some sample text as in the article example.
Merge pull request #2 from Thinkful/clean

Merged in Clean branch