Mention that the host may also be changed with ENV variables
Mention that the host may also be changed with ENV variables

Was moving server, and re-installing crontab-ui. I need to access it from another pi in my home network, and stumbled upon how to set the host. Thought it was be good to mention in the main README.md.

Thanks for the awesome software by the way!
alseambusher/crontab-ui