Removes ngrok as a tunneling option as this tool violates it's terms of service

[russorat]

PM for ngrok here. This tool directly violates the ngrok Terms of Service even when used for educational purposes only. We kindly request that ngrok be removed as an option in your tool. Please consider replacing it with other options from this list.

To learn more about how ngrok combats abuse, see https://ngrok.com/abuse and https://ngrok.com/tos .

• ngrok is not anonymous and can not be used to hide your identity.
• ngrok directly exposes your public IP address to anyone who sees the ngrok url you send them and in an http header.
• ngrok will ban your account if you use this tool.
• ngrok adds an interstitial page to all requests warning anyone viewing the page that the site is hosted by ngrok.

This PR attempts to remove ngrok from this tool. I've also fixed a few spelling errors.