paper-tooltip: multiline tooltip

[jnkroeker]

At present, cannot write a multiline tooltip

[panthony]

There are no such thing as multiline tooltip according to the MD specs:

https://material.io/design/components/tooltips.html

So I don't think this will change for paper-tooltip, if you need this you should probably either extend the component for your particular case or use another tooltip/popover related addon.