Feature summary (what you would like to be able to do and where):
Right now, extension settings are scattered between interface messages and LocalSettings.php. It would be very cool to combine them on one setting page.

Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Renaming categories, links to help pages, moving away from translatewiki.net where it is not needed.

Benefits (why should this be implemented?):
The convenience of fine-tuning the extension for administrators.

Because Babel stores configuration in interface messages and in LocalSettings.php, this consists of two migrations, see subtasks.