[RfR] New course guidance

[liamjberrisford]

Closes #234

[felicityguest]

Thank you for putting this guidance together, @liamjberrisford - it's going to prove very useful. I think we could simplify it to more easily ensure adherence to the timeline, so I've included some comments to that effect. If you'd like to discuss any aspects, please do let me know.

[liamjberrisford]

@felicityguest I’ve addressed the outstanding queries and consolidated the checklist and timeline into a single, streamlined document to more clearly reflect each step. I’ve also removed items rendered obsolete by the recent website updates, for example, manual accessibility checks are now automated through our CI pipeline. Would you mind taking another look? Apologies that some of it has changed a fair amount!

[github-actions]

🚦 Pa11y Accessibility Report

Running Pa11y on 1 URLs:

file:///__w/CfRR_Courses/CfRR_Courses/_build/html/contributing/new_course_checklist_timeline.html - 0 errors

✔ 1/1 URLs passed

⚠️ Any errors likely originate from the source file (e.g., filename.md, filename.ipynb).

[liamjberrisford]

@felicityguest The changes discussed have now been implemented and the content is ready to be reviewed again.

[liamjberrisford]

@felicityguest The review changes have now been added to the guidance and are ready for review.