DOCS: New workflows and concepts pages. (#1608)

* Started adding new concepts and workflow content to documentation

* Added embedded actions workflow page

* added actions asset workflow page

* added docs samples folder (may remove later!)

* Further work on diagrams including fixing fallback font issue

* latest work on concepts & workflows doc sections

* Adding more quick-start style info to the workflows page

* reorganized docs examples

* Split Components page into separate PlayerInput and PlayerInputManager, and fixed links.

* Tweaked docs example scripts and scenes

* Moved relevant quick start guide to PlayerInput page, adjusted TOC, updated screenshots.

* Adjustments mainly to TOC and intro / landing pages

* removed unnessecary text about supported devices from intro

* consolidated Introduction and index, and removed now-unused quickstartguide page

* Various final 'snag list' fixes to be ready for v1.5 publish.

Modifications to Actions page to fit with other new content including changes to sample code, text and screenshots. Moved extra concepts to concepts page. Added note about contributing to docs via feedback form. Added notes about samples using variety of workflows.

* Changed title of index page and updated changelog.

* Run formatting script to reformat files

* removed obsolete images

* Fixed  broken links in docs (plus a small amount of text improvement)

* Fixed broken HelpURLs in PlayerInput and PlayerInputManager components

* FIX: Documentation test verifying and checking MonoBehavior URL validity was requiring anchors to be present and wasn't producing meaningful error messages. This have been updated to pin-point violations and their source and what is the underlying cause.

* Disabling auto-generate C# script from DocsExamples assets to avoid CI issues on mac interfering with CI runs

Co-authored-by: Håkan Sidenvall <[email protected]>
Co-authored-by: James McGill <[email protected]>

Author: 3 people