[tracking] Scientific Python using MyST Engine

[choldgraf]

The Scientific Python project develops tools, standards, and community across the ecosystem of open source tools for scientific python. They have been developing a Hugo theme that mirrors the PyData Sphinx Theme design, but are interested in using a single document engine instead of maintaining two separate themes.

They're particularly excited about working with a documentation project that encourages external contributions and has pathways for joining a community. They're interested in using MySTMD for this, but would need some guidance in how they could accomplish this and contribute.

I had a conversation with @stefanv to scope out the kind of functionality they'd need in the short/long-term. We also discussed that he may have cycles to contribute to MyST to help make this happen, and is keen on helping with this project more!

Goals for this tracking issue

So this is a two-part tracking issue with the following goals:

1. Develop the MyST Engine so that it can meet the needs of the Scientific Python project.
2. Develop @stefanv into a contributor of MyST, with this functionality as a motivating driver for his cycles.

So I suggest that we use (1) to guide @stefanv's time, and make sure that we have issues shaped that he can contribute to that feed into these goals. I've spoken with @agoose77 and he'll use some of his capacity to work with @stefanv on this. It'd be great if others on the team could help as well so that we can grow the maintenance capacity on the project.

Major things that Scientific Python needs

Here are the major issues that we'd need to improve in order for SP to use the MyST Engine for its website and/or themes. We'll update this list if more come to mind:

Short-term needs

1. Landing Pages with widget layouts myst-theme#474 (to mimic their Hugo landing page)
2. Add support for loading user-defined CSS stylesheet myst-theme#321 or Support custom CSS classes for blocks of content #857 (so that they can apply the SP styling to a base theme easily)
3. Blogs and views of content based on page metadata (e.g. for blogs, galleries, site navigation, etc) #840 (so the SP blog could be hosted with MyST, similarly for sub-projects)

Longer-term needs

1. Add support for API documentation generation #1259 (so that sub-projects can use MyST in their documentation)
2. Add support for translations / internationalization / localization of page elements #166 (so that multi-lingual sub-projects like NumPy could use the MyST engine)