Support of button[role=link]

[kulturbande]

Hey there,

currently Pico is supporting [role=button] but not [role=link]. There are a few case, where you have to use a button for technically reasons (e.g. Logout Button), but it should behave like a link. For example in a dropdown with a few other links I want to have as the last menu point a log out - button, but it should not break the appearance of the dropdown.