[FEATURE] Add more guideline documentation, fix "TODO" issues in
guideline

Some sub-pages had not been added so far and the links to them were
commented out, but in a way that doesn't work in GitHub markdown. This
change adds these subpages and enables all the links to them.

Change-Id: I2a4e13d054a578800637e90018243a93dff22101
Merge "[FEATURE] Add more guideline documentation, fix "TODO" issues in guideline"