PyPI publish && mkdocs deploy actions

[northwestwitch]

This PR adds | fixes:

• github action to publish the repo to PyPI when a new version is created (triggering it now with this PR, and changing the action later) (fix #234)
• mkdocs deploy when a new version is created (triggering it now with this PR, and changing the action later)

How to test:

• It's github actions. The mkdocs publishing works:

• For the PyPI publishing I need someone with access to the PyPI repo to create a token!

Expected outcome:

• [ ] Both actions should be triggered when a new release is created

Review:

• [ ] Code approved by
• [ ] Tests executed by
• [ ] "Merge and deploy" approved by

This version is a:

• [ ] MAJOR - when you make incompatible API changes
• [x] MINOR - when you add functionality in a backwards compatible manner
• [ ] PATCH - when you make backwards compatible bug fixes or documentation/instructions

[northwestwitch]

[northwestwitch]

Pushing the latest version to PyPi worked after being able to create a secret (thanks @moonso). I am now changing this action to be triggered only when a new release is published and then I'll merge!