Enhancing Templating component documentation

[weaverryan]

Recommended sections:

• Introduction
• Installation
• Usage

[GromNaN]

See PR #1151

[weaverryan]

This has been bootstrapped, but there are some additional topics that we should still cover:

• details about EngineInterface
• helpers
• globals
• caching
• AssetHelper
• output escaping

[wouterj]

I don´t think this issue should be closed. A lot of topics aren't covered yet. Most of the topics are covered in the cookbook/templating/php article. Someone should move those topics from that article to this component article and put a link in the cookbook article.

[weaverryan]

Good catch - I've re-opened and modified the ticket title to be accurate to what we need now.