Migrate GYP docs over from the wiki.

Migrate GYP docs over from the wiki.

This CL migrates the GYP documentation over from the code.google.com
wiki:

Given that code.google.com is shutting down, and given that
the Gitiles browser that we use to view the source code supports
rendering markup (much like GitHub does), it seems reasonable to
migrate all of of the wiki content into the repository directly.

This CL is a first draft attempt at that. It was created by
using the code.google.com exporter to export to a temporary repo
on GitHub, and then the translated Markdown content was checked into
the GYP repo on chromium.googlesource.com. The translated content
was manually edited a bit to reformat things (text was wrapped,
tables of contents were added, lists and tables were adjusted)
but the content was unchanged from the wiki as of the date
of this CL.

R=bradnelson@google.com, bradnelson@chromium.org

Committed: https://chromium.googlesource.com/external/gyp/+/c5859a298166ce6ed3496175100c45f565f74cf8

[Dirk Pranke, 2015-04-01 02:38:15]

please take a look ... I think this gets things approximately equal to what the
wiki has, but I can't easily point you at a demo (you could see if if you ran a
local gitiles instance).

I think perhaps the best thing to do is to just land the patch as-is, and then
we can view the contents on the live site and edit in subsequent patches.

Thoughts?

[bradn, 2015-04-01 18:30:58]

bradnelson@google.com changed reviewers:
+ bradnelson@google.com

[bradn, 2015-04-01 18:30:58]

migration strategy sounds reasonable.
LGTM

[Dirk Pranke, 2015-04-01 22:27:09]

Committed patchset #1 (id:1) manually as
c5859a298166ce6ed3496175100c45f565f74cf8 (presubmit successful).