doc: added new article on contributing to hacktoberfest

[Timonwa]

Please describe the changes this PR makes and why it should be merged:

I added an article on how people can contribute to Million.js this Hacktoberfest.

Status

• Code changes have been tested against prettier, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating

Semantic versioning classification:

• This PR changes the codebase
  • This PR includes breaking changes (methods removed or renamed, parameters moved or removed)
  • This PR changes the internal workings with no modifications to the external API (bug fixes, performance improvements)
• This PR only includes non-code changes, like changes to documentation, README, etc.

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
million	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 4, 2023 5:03am
million-kitchen-sink	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 4, 2023 5:03am
sink	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Oct 4, 2023 5:03am

[coveralls]

Pull Request Test Coverage Report for Build 6392597640

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 25.691%

---

Totals
Change from base Build 6384112791:	0.0%
Covered Lines:	1256
Relevant Lines:	5081

---

💛 - Coveralls

[Timonwa]

@tobySolutions

[tobySolutions]

I don't see your changes in deployment though @Timonwa. Um, can you just do a screen recording?