Apply styles via 'class' or stylesheet? about canvas-formatted-text

[travisleithead]

Per PR #39, styles can be grouped into an object and applied per text run or for all text runs. However, no "cascading" or selector-based logic is in place. It seems potentially useful to be able to merge two or more separate groups of properties together, but I want to avoid adding that complexity until/unless there's a string use case for it, as workarounds to manually merge properties together into new groups is totally possible.

[travisleithead]

Hoping FormattedTextStyle can fit the bill for most use cases.