feat(holiday): australia regional holidays

[curbengh]

What is it?

• Bugfix
• Feature
• Codebase improvement

Description of the changes in your PR

• Re-add regional holidays removed by Holidays update #173, at least until an appropriate automation and UI are in place.
• Source

Acknowledgement

• I read the contribution guidelines.

[tswistak]

IMHO, you should rather modify the generator (https://github.com/FossifyOrg/Calendar/tree/master/.github/workflows/holiday-generator) to also consider regional holidays, not add them manually. They will get lost when the generator runs next time.

Another thing, as @naveensingh said in his comment (#173 (comment)):

Let's wait for some user feedback before making any further changes.