Links to FAQ, Cheat Sheet, Cookbook, gMock for Dummies

Renaming doc files to make the file names more palatable and in preparation for including documentation in sync process

Removing make and automake. The only supported build systems are Bazel internally and CMake community supported

This step is no longer necessary. The configuration given in the
googletest README.md is sufficient to bring in all the googlemock
headers.

Per the review comments.

Typos, punctuation & broken links

Issue #1028

Adds instructions for how to add gtest and gmock to
another CMake project directly. Downloading of the
googletest sources happens as configure time, allowing
it to be added to the main build directly via the
add_subdirectory() command. This ensures googletest is
built with the same compiler settings, etc. and will
typically result in a more robust and more convenient
build arrangement.