Color Documentation

- treat Color, ARGB, etc as things not requiring definitions
- fix links to Anti-alias, RGB-565
- finish everything marked incomplete, color and elsewhere
- add #Code blocks for #Typedef

R=caryclark@google.com
Docs-Preview: https://skia.org/?cl=128547
Bug: skia:6898
Change-Id: Icf12fe70bc2bf1a8b1a5b31380b2454610949f23
Reviewed-on: https://skia-review.googlesource.com/128547
Reviewed-by: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
27 files changed