[Feature] Some changes to package settings main menu entry.

This commit:

1. In lines the settings and keybindings of the main menu entry with that
   of the command palette entry by having the `default` arg.

2. Provides a documentation menu entry to open the README directly in the
   browser.

Author: UltraInstinct05

resources/Main.sublime-menu

@@ -13,12 +13,26 @@
                             {
                                 "caption": "Settings",
                                 "command": "edit_settings",
-                                "args": { "base_file": "${packages}/CommandsBrowser/resources/CommandsBrowser.sublime-settings" },
+                                "args": {
+                                    "base_file": "${packages}/CommandsBrowser/resources/CommandsBrowser.sublime-settings",
+                                    "default": "// Settings in here override those in \"CommandsBrowser/resources/CommandsBrowser.sublime-settings\"\n\n{\n\t$0\n}\n",
+                                },
                             },
                             {
                                 "caption": "Key Bindings",
                                 "command": "edit_settings",
-                                "args": { "base_file": "${packages}/CommandsBrowser/resources/Default.sublime-keymap" },
+                                "args": {
+                                    "base_file": "${packages}/CommandsBrowser/resources/Default.sublime-keymap",
+                                    "default": "// Key bindings in here override those in \"CommandsBrowser/resources/Default.sublime-keymap\"\n\n[\n\t$0\n]\n",
+                                },
+                            },
+                            { "caption": "-", },
+                            {
+                                "caption": "Documentation",
+                                "command": "open_url",
+                                "args": {
+                                    "url": "https://github.com/Sublime-Instincts/CommandsBrowser#readme"
+                                }
                             }
                         ]
                     }