Add support for message header

[kotnik]

In Homer we can have a header message before all the services, something like this:

message:
  url: "http://192.168.88.50:8099/endpoint/"
  style: "is-danger"
  title: "Service status"
  content: "Waiting for results from statping..."

This is very useful to integrate various services on the dashboard, my example is to show the uptime status of all the services in the dashboard.

It is the only Homer-like feature that bender is missing, and I hope you would consider adding it.

[jez500]

Hi @kotnik Sure, I can look at adding this, looks pretty straightforward