Make underline style use span and css by default #1212
Description
Is your feature request related to a problem? Please describe.
On Calypso and Gutenberg the underline format is represented by using the span element in combination with a css style.
While Aztec supports reading that style, when it applies the underline it uses the u element instead
Describe the solution you'd like
Instead of applying the <u> element let's apply a span with the css style like this <span style="text-decoration: underline"> </span>
Describe alternatives you've considered
Additional context