Setting up translation components in Weblate can be tricky in some cases, especially if you lack knowledge of the translation format you are using. Also this is something we wanted to automate from the very beginning, but there were always more pressing things to implement. But now the time is coming as I've just made first beta release of translation-finder, tool to help with this.
The translation-finder will look at filesystem (eg. checked out repository) and tries to find translatable files. So far the heuristics is pretty simple, but still it detects just fine most of the projects currently hosted on our hosted localization platform. Still if you find issue with that, you're welcome to provide feedback in our issue tracker.
The integration into Weblate will come in next weeks and will be able to enjoy this new feature in the 3.3 release.