Update wording in the add-on manifest

Author: soulim

extension/manifest.json.tmpl

@@ -3,7 +3,7 @@
   "name": "Q: process pages with your scripts",
   "short_name": "Q",
   "version": "${Q_EXTENSION_VERSION}",
-  "description": "Q allows you to send web pages to your external scripts for further processing.",
+  "description": "Q allows you to send web pages to your scripts for further processing.",
   "author": "Alexander Sulim",
   "homepage_url": "https://github.com/soulim/q/",
   "permissions": ["nativeMessaging", "activeTab", "notifications"],