Add: use our search-paths to find fonts based on relative filenames too #8482
Motivation / Problem
Given how OpenTTD works, you would expect that you can put
This allows "small_font = ./myfont.ttf", with "myfont.ttf" located
Tested on both Linux and Windows.
Checklist for review
Some things are not automated, and forgotten often. This list is a reminder for the reviewers.