[FEATURE] Add instructions on how to build the documentation

[darigovresearch]

Is your feature request related to a problem? Please describe.
New users will not know how to build the documentation if they wish to make contributions

Describe the solution you'd like
Small introduction & instructions on how to build either in the docs or the readme

Describe alternatives you've considered
Could be only in either the readme or the docs but would be helpful to have both depending on where the user starts from

Additional context
N/A

[drspangle]

This isn't necessary anymore since the docs get automatically rebuilt on every release.