feat: Support Korean Language

[tienipia]

Checklist

Please put "X" in the below checkboxes that apply::

• If committing a bugfix, I have tested it in different browsers (Chrome, Firefox, Safari).
• If committing a new feature, I have first submitted an issue (Please note: you are free to open PRs for non-issued features, but opening an issue increases your chance of a successful PR).
• If committing a new feature, I have also written an appropriate test suite for it.

I have tested the following:

• Qalendar component in month mode.
• Qalendar component in week mode.
• Qalendar component in day mode.
• All of the above modes on emulated mobile view.
• Dragging and dropping events.
• Resizing events in day/week modes.
• Clicking events to open event dialog.

This PR solves the following problem**.

Additional resource for Korean support.
No any changes, only resource. (Just got removed trail whitespace in Polish resource)

How to test this PR**.

For example:

1. Feed X and Y in the events-Prop.
2. Click Z or A.
3. Confirm that B is displayed.

[tienipia]

@tomosterlund Hello. it's very simple PR, could you please merge it?

[coveralls]

coverage: 97.607% (+0.03%) from 97.575%
when pulling dd648da on tienipia:master
into 093a48f on tomosterlund:master.

[tomosterlund]

Hey there. The e2e tests are failing. Might be that just the text rendering has changed in the Chrome version used by Cypress, but to know for sure I would have to investigate it.

Since I'm not spending any time on adding features here, the best alternatives would be:

• have a look at schedule-x, which is better in all ways anyway and still maintained: https://schedule-x.dev/
• release your own fork of this repo via npm.