Adding Sardinian (#5984)

* Create main-sc.json

* Create languages-sc.json

* Update languages.json

* Update main-sc.json

(just a couple of minor edits to the translation)

* Update BuiltinLanguages.native.js

adding Sardinian

* trailing spaces corrected

* Update BuiltinLanguages.native.js

* Update BuiltinLanguages.native.js

fixed spaces

* Update main-sc.json

react/features/base/i18n/BuiltinLanguages.native.js

         main: require('../../../../lang/main-ptBR')
     },
 
+    // Sardinian (Sardinia)
+    'sc': {
+        languages: require('../../../../lang/languages-sc'),
+        main: require('../../../../lang/main-sc')
+    },
+
     // Russian
     'ru': {
         languages: require('../../../../lang/languages-ru'),