Remove unmaintained languages + minor localization tasks (#587)

* Fix missing string

* Localize "loading recipes"

* Remove unmaintained languages

Remove support for Danish, Portuguese and Chinese Traditional,
since their current translation state is <20%

frontend/src/store/modules/language.js

@@ -5,10 +5,6 @@ const state = {
       name: "English",
       value: "en-US",
     },
-    {
-      name: "Dansk (Danish)",
-      value: "da-DK",
-    },
     {
       name: "Deutsch (German)",
       value: "de-DE",
@@ -29,10 +25,6 @@ const state = {
       name: "Polski (Polish)",
       value: "pl-PL",
     },
-    {
-      name: "Português (Portuguese)",
-      value: "pt-PT",
-    },
     {
       name: "Svenska (Swedish)",
       value: "sv-SE",
@@ -41,10 +33,6 @@ const state = {
       name: "简体中文 (Chinese simplified)",
       value: "zh-CN",
     },
-    {
-      name: "繁體中文 (Chinese traditional)",
-      value: "zh-TW",
-    },
   ],
 };