Add techdocs to registry ui

[notlee]

There's a lot going on here, so maybe a good time to get a preliminary review. :)

Todo

• Improve test coverage.
• Replace JSDoc/SassDoc mock data with real component data.
• Remove or do something useful with codedoc right sidebar? Gabi & me: remove for now
• Add content to initial codoc view -- the first class, or mixin that matches the component name?
• Filter demos same as code docs? Gabi & me: not yet
• Contribute to solve or workaround code parsing issue.
• Add syntax highlighting for diff and sh.

Resolves Financial-Times/ft-origami#574

[gvonkoss]

oSyntaxHighlightAll() ?

[notlee]

Some screenshots:

When a component has JS but no valid JsDocs exist:

[notlee]

Constructors with many params do not display them in their title.

But those with few do:

[rowanmanning]

Spoke in-person, we're going to merge and get onto QA