CRM-20600 - Add chapters for AngularJS and AssetBuilder

[totten]

Depends: civicrm/civicrm-core#10085

[seancolsen]

@totten I see that civicrm/civicrm-core#10085 has now been merged. I'd like to get this content into the Dev Guide because it looks really useful. Is there more work to do here?

[seancolsen]

I propose changing this section to the following:

  - AngularJS:
    - AngularJS: framework/angular/index.md
    - AngularJS Quick Start: framework/angular/quickstart.md
    - AngularJS File Names: framework/angular/files.md
    - AngularJS Loader: framework/angular/loader.md
    - AngularJS Modifications:  framework/angular/modify.md

Reasons:

• Use index.md for hackable URLs (This change also requires a file rename)
• Use more descriptive menu item labels (as described here, so that the <title> element better reflects the page content).

[totten]

Rebased (to address merge-conflits) and updated to use this structure.

Note: I also renamed "Modifications" to "Changesets". This matches terminology that is used in the code, and it feels a bit more precise.

[seancolsen]

I propose removing this "Additional pages" section because it's a duplication of the listing of pages in the menu and thus is prone to falling out of sync if we add/remove/re-order these pages.

[totten]

I've removed the "WIP" label. Most sections should be presentable.

I don't have a strong opinion on whether to merge now or to wait a bit. There is one page (framework/angular/changeset.md) which is incomplete and has a prominent disclaimer at the top. On the other hand, I'm not sure if that page should block the others.

[seancolsen]

Exciting! This stuff looks really good. I have a couple follow-up points for which I'll create tickets.