Support 3 and 4 letter month parameters for toFormat

[edwardmjackson]

Appreciate the locale difficulties here, but is there a way to support 3 and 4 letter parameters (e.g., MMM, and MMMM) for the toFormat method?

Currently, I see this:

(new CalendarDate("2020-07-06")).toFormat("yyyy-MMM-dd") // 2020-077-06

Ideally, it would return 'Jul'.

I can do workarounds by converting to a JS Date or using MomentJS, it's just a bit messy.

[co-sic]

Hey @edwardmjackson . Sorry for the late reply, i did not see this discussion until now. I created a PR to have more formatting options: #277