Markdown Support

We do have some simple HTML styling options such as <b> <i>.

Since Markdown is pretty supported everywhere, I would love to be able to use Markdown to format Pushover notification messages, such as **bold** or *italic*. Pretty much the same styling options that we are using now with HTML just using Markdown.

Why? Some services do not support HTML styling of notifications (looking at you Grafana), but I would love to have styling or even better: hyperlinks.