Need the `font-style` property documented

[rroberrt]

As a user
I need the font-style CSS property documented
So that I can use it for reference when building HTML email templates

Details & Assumptions

• MDN: https://developer.mozilla.org/en-US/docs/Web/CSS/font-style

Acceptance Criteria

Given the `font-style` property is implemented
When I search for "font-style" in the search bar
Then I should see data about mail client compatibility for the `font-style` property