Finalise script behaviour

[lilyminium]

Is your feature request related to a problem? Please describe.
The user guide uses a number of scripts to make tables, page stubs, and so on. Should these be put in conf.py to get run every time the docs are built, or should they be manually run? If they are automatically executed, how does that work with widgets that require visualisation in the browser first?

Describe the solution you'd like
1. Automatic execution

• Update conf.py and add comments explaining what's going on
• Either turn off automatic execution of notebooks with NGLview widgets, or work out if selenium is a solution on Travis
• Remind contributors to temporarily turn off automatic execution if they're using sphinx-autobuild or it will refresh to infinity

or
2. Manual execution

• Remind contributors to re-execute scripts in pull request template. Put them all in generate_all.sh