Update English description

src/_locales/en/messages.json

@@ -4,7 +4,7 @@
         "description": ""
     },
     "extShortDesc": {
-        "message": "Point & click to forbid/allow any class of requests made by your browser. Use it to block scripts, iframes, ads, facebook, etc.",
+        "message": "Point & click to forbid/allow any class of requests made by your browser. A fork of Raymond Hill's uMatrix.",
         "description": "this will be used as short description in web stores: MUST BE 132 characters OR LESS"
     },
     "dashboardPageName": {