Improve some docs on rbt post, and add anchors.
Review Request #8730 — Created Feb. 8, 2017 and submitted — Latest diff uploaded
This makes a couple small improvements to the documentation on rbt post, preferring rbt post -u over -r, and removing the (outdated) documentation for -g. It also adds a bunch of anchors we can use to link to usage documentation for different SCMs. Future changes will build upon this by splitting out the pages into per-SCM pages.
Built the docs and tested the references.