added chinese translations (#1310)

assets/js/KimaiLoader.js

@@ -40,7 +40,7 @@ export default class KimaiLoader {
 
     constructor(configurations, translations) {
         // set the current locale for all javascript components
-        moment.locale(configurations['locale']);
+        moment.locale(configurations['locale'].replace('_', '-').toLowerCase());
 
         const kimai = new KimaiContainer(
             new KimaiConfiguration(configurations),

assets/js/plugins/KimaiFormSelect.js

@@ -105,7 +105,7 @@ export default class KimaiFormSelect extends KimaiPlugin {
         }
 
         options = {...options, ...{
-            language: this.getContainer().getConfiguration().get('locale'),
+            language: this.getContainer().getConfiguration().get('locale').replace('_', '-'),
             theme: "bootstrap",
             matcher: matcher
         }};