Match the boilerplate master & Remove TODO done by grunt
Modifications as follows:
1. Remove TODO lines that grunt already handles
2. Remaining TODO lines are marked as @TODO, same as the master.
3. Remove screen_icon() function in root/admin/views/admin.php as done in the master (since this function is deprecated)
4. Change languages/ to /languages/ in load_plugin_textdomain function in root/public/class-plugin-name.php, as done in the original boilerplate master.
5. Other  Small Modifications as done in the original boilerplate master.