Update en.json

Author: CrazyPython

locales/en.json

@@ -5,7 +5,7 @@
 	"Intro": "Intro",
 	"History": "History",
 	"New guest note": "New guest note",
-	"Collaborate with URL": "Real-time collaboration",
+	"Collaborate with URL": "Realtime collaboration",
 	"Support charts and MathJax": "Supports charts and MathJax",
 	"Support slide mode": "Supports slide mode",
 	"Sign In": "Sign In",