i18n: Add Serbian back

src/invidious/helpers/i18n.cr

@@ -1,8 +1,6 @@
 # "bn_BD"   => load_locale("bn_BD"),   # Bengali (Bangladesh)  [Incomplete]
 # "eu"      => load_locale("eu"),      # Basque  [Incomplete]
 # "sk"      => load_locale("sk"),      # Slovak  [Incomplete]
-# "sr"      => load_locale("sr"),      # Serbian  [Incomplete]
-# "sr_Cyrl" => load_locale("sr_Cyrl"), # Serbian (cyrillic)  [Incomplete]
 LOCALES_LIST = {
   "ar"      => "العربية",               # Arabic
   "cs"      => "Čeština",               # Czech
@@ -32,6 +30,8 @@ LOCALES_LIST = {
   "pt-PT"   => "Português de Portugal", # Portuguese (Portugal)
   "ro"      => "Română",                # Romanian
   "ru"      => "русский",               # Russian
+  "sr"      => "srpski (latinica)",     # Serbian (Latin)
+  "sr_Cyrl" => "српски (ћирилица)",     # Serbian (Cyrillic)
   "sv-SE"   => "Svenska",               # Swedish
   "tr"      => "Türkçe",                # Turkish
   "uk"      => "Українська",            # Ukrainian