Use tracetheme dimensions and theme

[Bisaloo]

Fix #131

[joshwlambert]

CI workflows are failing, does the tracetheme package need to be added to Remotes in DESCRIPTION for it to be correctly installed in setup-r-dependencies?

[Bisaloo]

I forgot about r-lib/actions#656.

We cannot put it in Remotes: because that would affect our ability to put packages on CRAN.

Two solutions:

• modify the pkgdown.yaml workflows to add our r-universe as a source repo
• add tracetheme in Config/Needs/website:, which will work out of the box but may mean that we see difficult results locally if tracetheme is not installed (EDIT: that would only fix the pkgdown wofklow, not the others)

What do you think?

[joshwlambert]

My initial preference is to add it to Config/Needs/website:, because functions from it are explicitly namespaced in the package, having it stated in the DESCRIPTION file is, IMO, more familiar, and is probably where someone would look for the dependency. However, I don't have a strong preference either way and both would satisfy to get this PR merged.

Another option would be to put tracetheme on CRAN, even if not intended for wider use, it may ease Epiverse development, but I understand that that is not a short term solution to this issue.