Hulu key c toggle subtitle

Currently Hulu web version video player doesn't provide a hotkey for toggling the video subtitle. This feature is being asked for quite some time in the community.

This extension is to provide the support for using the keyboard 'c' key to toggle the video player subtitle.

Steps to use:
1. Install the extension. The extension icon will grey out when the tab is not on a hulu video url.
2. When you navigate to hulu video url (i.e "https://www.hulu.com/watch/*"), you will see the icon green.
3. Now you can use the keyboard key 'c' to toggle the video subtitle.

Note: the very first c might not take effect. Please try a few more key press and it should work.