remove generated build doc from mcsapi in favor of its Readme.md in Github

Currently we have two documents that document the build process of mcsapi. The build instructions in Github's Readme.md which is updated frequently and the build instructions in /docs that haven't been updated in 9 month.

It was decided that we remove the build instructions in /docs in favor of Readme.md to avoid confusion and double effort in maintaining both.

The usage_guides in the /docs folder are not affected by this MCOL and shall remain.