.text-bold Class(es)

While `.text-bold` seems like an obvious addition after adding `.text-italic` in Frow 3.3, there's actually a bit more complexity there with how to handle what the class should do.

Is the correct default behavior to add `font-weight: bold`, or is it `font-weight: bolder`. Should `.text-bolder` and `.text-lighter` exist?

I did not create `.text-oblique` when including `.text-italic` as I didn't see the need. The bold classes need the same evaluation.

Start by locating the existing `.text-italic` implementation and reviewing the framework's utility-class conventions. Resolve the intended behavior and scope for `.text-bold`, including whether `.text-bolder`, `.text-lighter`, or `.text-oblique` belong; the issue is complete when that decision is reflected in the implementation.

Written by the indexing model from the issue text.