Allow tracking pkgdown/

[pratikunterwegs]

This issue is to flag that we may want to add the pkgdown/ directory to tracking in the future.

This folder can contain important files we want to commit. Do you have any issues that lead you to add it here?

Originally posted by @Bisaloo in #54 (comment)

[Bisaloo]

If you don't want to have the logos, you can delete them. They will be regenerated by pkgdown as necessary (as they are now). But the pkgdown/ folder should not be .gitignored. It is a valid pkgdown config folder that can contain valuable information (example in pkgdown itself: https://github.com/r-lib/pkgdown/tree/main/pkgdown)

[pratikunterwegs]

The example contains mostly the pkgdown YAML, which we already include in our top-level directory (across packages, based on {packagetemplate}) - does the locations of this file also need to be changed?

[Bisaloo]

Both locations are valid so no need to change it