Add comments the disk layout files, and local README file.

Json doesn't support comments of the normal type, so we use keys of the name
"_comment" will will be ignored when layout files are parsed by cgpt.py.

Adjust cgpt.py to ignore "_comment" keys for layout names, and update to
pass lint requirements.

Move web documentation to a local README kept with the code.

BUG=chromium:323688
TEST=Built, cgpt debug output diffed between original and new. Identical.

Change-Id: I762133a993771b84bda9326ea7052b84f5334df3
Reviewed-on: https://chromium-review.googlesource.com/181830
Tested-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Don Garrett <dgarrett@chromium.org>
3 files changed