Use Doxygen Awesome and flesh out Doxygen documentation

[seabbs]

Currently this looks a bit basic. See here: https://jothepro.github.io/doxygen-awesome-css/index.html#autotoc_md11

[jamesmbaazam]

Happy to lead this applying learnings from https://epiforecasts.io/EpiNow2/stan/index.html.

This would involve (ideally as sub-issues but I don't have the rights here)

• Fixing the title of the stan reference which currently says "epinowcast" instead of "primarycensored"
• Adding function groups
• Generating the doxygen docs with the new groups to improve navigation.

[seabbs]

Im quite keen to do a new release soon. Any time chance you might have time to take this on in the near feature James?

[jamesmbaazam]

We should have this closed by close of next week. I'm away on Monday so will pick it up when I return.

Feel free to assign me.