Build tool to automatically compile sections of the FATES code to provide as reference to the user

[glemieux]

Is your feature request related to a problem? Please describe.
There are some parts of the fates code that we would like to be able to reference in the user's guide, such as a table of all the possible history output variable options, as opposed to just pointing them to the code itself, which can break during refactoring and other updates.

Describe the solution you'd like
Develop a tool using docstrings or some other method to reference the fates repo main code. Ideally this would automatically be kicked off if an update to the relevant sections of code were noticed.

Describe alternatives you've considered
Not really

Additional context
N/A