[DOCS] Define our computational content with markdown and use --execute when building our site

[choldgraf]

The MyST documentation has a single .ipynb file and assumes that this file has pre-executed content inside. The docs are built without the --execute flag so no computation happens.

I think it would be helpful if we instead converted that to (or added in addition) a markdown file with computation and built the documentation with --execute. This would make it easier to show off functionality like {eval} and {code-block}, and ensure that they work as expected.

[rowanc1]

Yep, was going to suggest this!

[choldgraf]

Cool - I think this could also be accomplished alongside the ReadTheDocs preview issue so that we can preview the computations in our PRs and get a lightweight "integration test for docs" out of it:

• 📖 Add ReadTheDocs automation #982

[choldgraf]

Also just noting that I have no idea how our docs is actually hosted, so it might be a helpful opportunity for @rowanc1 to show how he implements this if we get it implemented outside of the RTD preview.

[rowanc1]

This has been implemented!