Update README for CM 10.1

Update to reflect:

1) CM .org changes
2) Fix 404 for Repo help and add in git help page
3) Point to cm-10.1 branch
4) Fix reference to buildbots to point to Jenkins instead

Patchset 2: White space, missed a .org and fixed grammar for Jenkins.
Patchset 3: Fix wiki link 404 due to short-url extension. Swap a few urls to https

Change-Id: I89510d6afcab0e1c302dd31884eeb130e9324142