lang url parameter (#296)

* lang url parameter

* add ?lang to readme.

---------

Co-authored-by: Miroslav Šedivý <sedivy.miro@gmail.com>

client/src/components/menu.vue

@@ -76,5 +76,12 @@
     about() {
       this.$accessor.client.toggleAbout()
     }
+
+    mounted() {
+      const default_lang = new URL(location.href).searchParams.get('lang')
+      if (default_lang && this.langs.includes(default_lang)) {
+        this.$i18n.locale = default_lang
+      }
+    }
   }
 </script>

client/src/plugins/i18n.ts

@@ -6,5 +6,6 @@ Vue.use(VueI18n)
 
 export const i18n = new VueI18n({
   locale: 'en',
+  fallbackLocale: 'en',
   messages,
 })