Add CI workflows / products (e.g. pkgdown?)

[pearsonca]

Is your feature request related to a problem? Please describe.
Not a code one, an engineering one (testing automation, linting / styling / etc checks)

Describe the solution you'd like
A subset of the epinowcast CI.

Describe alternatives you've considered
Just manually doing checks - small enough scale at the moment, but does need so of the other static analysis added.

[seabbs]

This should be relatively easy as a copy and paste job. At some point we really want shared organisation CI to make this easier to handle.

[pearsonca]

Re copy paste: I will just do that, trying to be sensible, and PR it.

Re the organizational bit: well, does it make sense to have this repo as a test case for that? (in which case, seems like the copy-pasta belongs to you or @Bisaloo or some such?)

[Bisaloo]

It's important to note there is no real way to have organization level CI on the free GitHub plan.

You can share a workflow across repos by using the organization level required workflow but it's lacking many features and it's already marked as deprecated.

All investment in terms of organization level orchestration, and in particular in terms of organization CI, seems to be going in GitHub Enterprise lately.