Docs cleanup

[RensDimmendaal]

This PR adds multiple fixes, mainly to the docs.

1. Dont run plash_view in index.ipynb as it opens browsers windows when running tests
2. Add app_id as cli command for ease of use
3. Rename aid to app_id for consistency
4. Add gh actions to deploy docs (TODO: add secret to repo)
   • deploy docs on merge
   • deploy docs on PR to a temp url if not made from fork or if PR has label 'docs-preview' (this to prevent abuse)
5. Several small docstring fixes.
6. CLI output of app url now supports custom domains
7. Move the examples folder to the root of the repo

Note: the GH actions needs some testing, hard to do offline.

[gitnotebooks]

Found 4 changed notebooks. Review the changes at https://app.gitnotebooks.com/AnswerDotAI/plash_cli/pull/25

[ncoop57]

Made some minor fixes to cli ref and to the github action for previewing and deploying