Add using on Read The Docs instructions

[mlncn]

This is a start to addressing #155

[chrisjsewell]

Thanks @mlncn some review comments above, also you may want to look at https://myst-parser.readthedocs.io/en/latest/develop/contributing.html#code-style, to ensure that the pre-commit check pass before commiting

[choldgraf]

Thanks for the contribution! Given how common it is for people to use RTD, do you think we could instead append this content as a final section to the getting started page? (https://myst-parser.readthedocs.io/en/latest/using/intro.html)

[chrisjsewell]

Yeh I wouldn't be adverse to that

[mlncn]

Will shift to appending and finally get this wrapped up later tonight!

[pradyunsg]

Hey @mlncn, is there any help you'd need to move this forward, or is the blocker just the number of hours in a day? :)

[mlncn]

@pradyunsg whoops yeah i should not be the blocker on this if you'd be willing to put the documentation updates in the right place! Thank you!

[astrojuanlu]

Hi folks, I would be happy to move this forward :) If @mincn ran out of stamina, may I open a new pull request with their commits?

[chrisjsewell]

Well I certainly won't stop you 😄

[choldgraf]

@astrojuanlu go for it - happy to review docs PRs 👍