Factor out other shared Actions to this repo

Various repos such as the R packages use a lot of the same shared, custom Actions. Where possible, we should factor out their Actions to a workflow or composite action in this repo.

[x] #2
[x] #28
[ ] R package linting (e.g. lint.yaml)
[ ] Build the R package website (e.g. pkgdown.yaml)
[ ] R package build matrix (e.g. R-CMD-check.yaml)

ccao-data / actions

Factor out other shared Actions to this repo #24