(pre). Activate the Intro page extra (Login -> Manage extras, choose it from the list)
1. Goto Login -> Manage extras -> Intro Page. There are two text fields:
'Enter text to be shown before the Enter button' and 'Enter text to be shown after the Enter button'.
Just enter your html directly into this fields and save.
If you load your page you will notice that the html code you have is not shown correctly, so lets do the next step:
2. Again, goto Login -> Manage extras -> Intro page. If you look into the text-boxes you will see how you inserted html code should look really like on your intro page.
Just do nothing
and push 'Edit'
This looks like it is a small bug. It could be possible that this bug will someday be fixed, so don't expect too much from this