Rhino docs show two search boxes

[kamilzyla]

Problem

Cause

The problem seems to have appeared after #597 was merged. A bump of RoxygenNote from 7.2.3 to 7.3.1 in this commit might have resulted in newer pkgdown dependencies being installed in the pkgdown.yml workflow after the merge which probably caused the problem to appear.

I had trouble reproducing the issue locally but I was finally able to do it by installing all the packages with the exact versions as printed in the log files of pkgdown.yml workflow. The issue seems to only appear when the site is built with pkgdown/build.R which is our solution for showing multiple documentation versions (#575). Probably the navbar_template.html was updated in {pkgdown} causing our copy to malfunction.

Possible approaches

1. Update navbar_template.html.
2. Inject the version switcher using before_navbar as discussed in this comment (avoid keeping a copy of a template).