updating help with new scripting parameter

Author: Chris Raynor

lib/help.js

@@ -202,6 +202,10 @@ module.exports = {
                     '  -v, --version\n' +
                     '    Displays the current version.\n' +
                     '\n' +
+                    '  -s, --silent\n' +
+                    '    Silent mode for scripting - commands will error with non-zero status code\n' +
+                    '    instead of waiting for prompt if not enough information supplied.\n' +
+                    '\n' +
                     'For a quick start guide, see https://www.firebase.com/docs/hosting.html\n');
     }
   },