feat: localization (#196)

* Started adding locale translations :)

* Added some more translations

* Working on translating even more pages

* More translations

* Added test default locale retrieval

* replace `intl.formatMessage` with custom `t` hook

* add more translations

* improve title syntax

* add more translations

* translate admin config page

* translated error messages

* add language selecter

* minor fixes

* improve language handling

* add upcoming languages

* add `crowdin.yml`

* run formatter

---------

Co-authored-by: Steve Tautonico <stautonico@gmail.com>

frontend/next.config.js

@@ -1,5 +1,4 @@
 /** @type {import('next').NextConfig} */
-
 const { version } = require('./package.json');
 
 const withPWA = require("next-pwa")({