Make pymapconv more Official™

#1696 removes some remnant references to the old mapconv, and there doesn't seem to be any map compiler tool repo in the org. There should be something on github at least pointing to the pymapconv repo.

Review #1696 and the pymapconv repository to determine where the old mapconv references were removed and how the repository should be pointed to from GitHub. Add the appropriate public pointer or repository reference so users can find pymapconv, and verify that no old mapconv reference remains.

Written by the indexing model from the issue text.