Run the `makemessages` command at the root of the repo to include the `ka-lite-submodule` sources.
Add the missing `CROWDIN_API_URL` constant.
Use the output directory of the *.po files instead of the `ka-lite-submodule` path when uploading to CrowdIn.
Merge pull request #219 from mrpau/hotfix/218-some-strings-aren't-being-pulled-by-makemessages-when-update_pot-is-run

Fix for #218-Some strings aren't being pulled by makemessages when update_pot is run