Improved documentation structure

Refactor Documentation

Starting point for a better documentation structure. Proposal from @racitup: It also really needs annotating with change history, especially settings (e.g. "Changed in v0.10.1").

Architecture

1. Description of Django, CMS, admin, Angular, bootstrap, SASS, Haystack & DRF integration
2. Features
3. Exclusions/ ToDo list (link to reserved github issue number?)
4. Compatibility (python, django, CMS, DRF, etc..)

Required component installation & what they're used for

1. python
2. node / npm
3. other (redis & elasticsearch?)

Database integration

1. Migrations
2. Fixtures - items to include all CMS plugins & CMS shop pages (i.e. search, watch-list, cart, checkout, etc..)

Minimum requirements

1. Settings
2. URLs 3a. Attaching CMS pages to Views 3b. Attaching DRF Views to URLs
3. Styling

Customisation

1. Models & admin
2. Product Categories
3. Overriding Templates & Styling
4. Modifiers
5. Serializers
6. Search

Known external plugins (& degree of recommendation) e.g. Paypal, currencies, modifiers.. If you let me know where the best place to put it is, I may even be able to contribute a draft!