Support spaces in labels

[choldgraf]

Describe the enhancement you'd like

It would be useful if it were possible to use spaces in labels, like so:

(my label)=
# My header

Ref for [](my label).

In executablebooks/meta#467 (comment) we discovered that, while reStructuredText supports spaces in labels, like .. _my label:, the MyST parser does not.

Benefit

This would be useful for people who are coming from the rST / Sphinx ecosystem, since this is already supported in rST. However it's probably not a huge number of people using labels this way because most seem to use - or _ for this kind of thing.

Implementation

The fix for this would probably somewhere around here:

mdit-py-plugins/mdit_py_plugins/myst_blocks/index.py

Line 116 in a0f7ffa

def target(state: StateBlock, startLine: int, endLine: int, silent: bool):

[welcome]

Thanks for opening your first issue here! Engagement like this is essential for open source projects! 🤗

If you haven't done so already, check out EBP's Code of Conduct. Also, please try to follow the issue template as it helps other community members to contribute more effectively.

If your issue is a feature request, others may react to it, to raise its prominence (see Feature Voting).

Welcome to the EBP community! 🎉