Post: MyST Parser 0.15

[choldgraf]

We released v0.15 of the MyST parser a few weeks back, we should write up a little post about the updates.

Let's try to follow the same pattern as our last blog post (https://github.com/executablebooks/meta/pull/400). We'll keep it relatively short and scoped to 255 character paragraphs so that we can easily turn it into a Twitter thread as well.

• [ ] Draft of post ready
• [ ] Comments / iteration on draft
• [ ] Make the blog post
• [ ] Thank the Sloan foundation in the post
• [ ] Create a twitter thread from post, link to post
• [ ] Done! 🎉

Changelog: https://myst-parser.readthedocs.io/en/latest/develop/_changelog.html#id2