Hi, and thank you for your interest!
Weblate is being translated using Weblate, a web tool designed to ease translating for both developers and translators.
Translation project for Weblate into Chinese (Traditional) currently contains 1753 strings for translation and is 92.1% complete.
If you would like to contribute to translation of Weblate, you need to register on this server.
Once you have activated your account just proceed to the translation section.