Add Ngrok + Wordpress + MySQL template

Add the Ngrok + Wordpress + MySQL template.

Unlike the default template, this one provides zero-configuration access to the Wordpress container through Ngrok. Simply watch the logs for the Ngrok URL and then copy-and-paste it into your browser to see your Wordpress instance running in Panamax.

Other configuration options are also available, including custom subdomains, domains, and HTTP authentication, all through configuring Ngrok with environmental variables.