docs: use new standard Open edX for documentation

[mariajgrimaldi]

Description:
This PR generates the new files structure for docs proposed in this how-to by the community members. This is how it looks rendered with a few modifications:

ISSUE:
#41

Dependencies:
None

Merge deadline:
ASAP

Installation instructions:
Just documentation

Testing instructions:
Just documentation

Reviewers:

• @felipemontoya

Merge checklist:

• All reviewers approved
• CI build is green
• Version bumped
• Changelog record added
• Documentation updated (not only docstrings)
• Commits are squashed

Post merge:

• Create a tag
• Check new version is pushed to PyPI after tag-triggered build is
  finished.
• Delete working branch (if not needed anymore)

Author concerns:
None for now

[openedx-webhooks]

Thanks for the pull request, @mariajgrimaldi!

As a core committer in this repo, you can merge this once the pull request is approved per the core committer reviewer requirements and according to the agreement with your edX Champion.

[felipemontoya]

This changes seem full reasonable to me. They affect the build format and not the content

[mphilbrick211]

Hi @mariajgrimaldi - just checking to see if this is ready to merge?

[openedx-webhooks]

@mariajgrimaldi 🎉 Your pull request was merged! Please take a moment to answer a two question survey so we can improve your experience in the future.

[pomegranited]

Hi @mariajgrimaldi ! Where can I see the newly rendered docs for this repo since this change was made? The readthedocs link on the README doesn't work anymore :(

[mariajgrimaldi]

Hi @pomegranited! We still need to deploy the new docs, I still need to finish writing them. But that's my priority! For the time being, you can reference this PR: #64