📘 DOC: Add default remark plugin config to docs as an easy copy-pastable snippet.

[jasikpark]

Can we add documentation that makes it easier to add extra plugins to remark? At the moment, we list the plugins used, but we don't document how to replicate the current config.

[jonathantneal]

I’m open to a PR here. Would you let me know if you’d be able to help out here, or if you feel this is now addressed? Don’t feel too much pressure. We’ll get someone on it!

[sarah11918]

I'm going to close this since we do now have examples of adding remark plugins!