Docs and Guides

[leandrocp]

Meta issue to track all the work necessary on docs and guides for v0.1

Beacon

• [x] CHANGELOG
• [x] #473
• [x] #474
• [x] Update ex_doc
• [x] Update the installation guide to fix and improve it based on feedback received
• [x] Update the "your first site" guide to fix and improve it based on feedback received
• [x] Review groups - modules may have been added or removed or are now @moduledoc false
• [x] Review module docs - it's not viable to document all the ~100 files we have at this moment so we need to add @moduledoc false to private modules or modules that do not impact users. Others we need to review module and functions docs adding a summary, examples, and notes.
• [x] Review and add missing @spec to public functions, eg: Content, MediaLibrary - only in the main API (main modules)
• [x] Review Beacon docs
• ~List all authz operations available~ (removed)
• [x] Write a "publish a blog" recipe that calls Content.list_published_pages/2 to list most recent pages and filter by tag
• [x] Write a quick guide showing the usage of beacon assigns, ie: calling @beacon in templates to access data like site name, path/query params, etc.
• [x] Brainstorm other guides that makes sense to write for v0.1

Beacon Live Admin

• [x] CHANGELOG
• [x] Review guides
• [x] Review module docs
• [x] Review function docs

Beacon Demo

• [ ] Update beacon_demo with latest changes