Add strings.

en.json

@@ -187,6 +187,15 @@
                     "title": "Language",
                     "select": "Select your language"
                 },
+                "sync": {
+                    "title": "Sync",
+                    "categories": "Sync Categories",
+                    "descriptions": {
+                        "appearance": "This will sync options such as emoji packs and message density.",
+                        "theme": "This will sync your chosen theme, colours and any custom CSS.",
+                        "locale": "This will sync your currently chosen language."
+                    }
+                },
                 "donate": {
                     "title": "Donate"
                 },