[DOC] Merge doc source

* Merge doc source from: https://github.com/anyway1021/eagle-doc
* Uploaded to http://eagle.apache.org/docs/latest/

So that contributors could send patch about code along with related docs in single PR.

Author: Hao Chen <hchen9@ebay.com>

Closes #901 from haoch/MergeDocSource.
83 files changed