Changing the way the translations are handled:

To make the Weblate integration simplier, this commit merge all
translations in yml files (there is no more distinction between
standards and settings strings)

This yml files will be handled by Weblate.

TODO: document the new translation process.

server/lib/settings.ts

@@ -23,7 +23,7 @@ function loc (key: string): string {
 }
 
 async function loadLoc (): Promise<void> {
-  const filePath = resolve(__dirname, '..', '..', 'languages', 'settings.reference.json')
+  const filePath = resolve(__dirname, '..', '..', 'languages', 'en.reference.json')
   if (!existsSync(filePath)) {
     throw new Error(`File ${filePath} missing, can't load plugin settings`)
   }