Update myst-parser version

[chrisjsewell]

Heya, I've seen a few people have started to use this in forks 😄
You might want to consider updating the myst-parser version, since I've been making quite a few improvements lately (it should now be relatively stable on v0.12).
See https://github.com/executablebooks/MyST-Parser/blob/master/CHANGELOG.md for details

[chrisjsewell]

Note also that, for correct compatibility between myst-parser and jupytext, you need jupytext>=1.6.
pip install jupytext==1.6.0rc0 is available as of today, with 1.6 proper to come in the next few days (edit: now available)

[ggorman]

Thanks for the PR @chrisjsewell :-)
Looks good. Do you mind adding jupytext>=1.6 to requirements.txt as per your comment above?

[chrisjsewell]

done 👍

[chrisjsewell]

gentle prod 👉