Added k-means notes

[moepotatoe]

Sources

Did you include the sources used in creating your contribution?

• [X ] Yes
• No

If you answered No to the last question:

Ensuring the quality of content within Data Science Notes is essential such that the collection is reliable. If you didn't utilize any sources for creating your contribution, could you please list your qualifications or add a link to your LinkedIn profile?

< replace this line with a brief description of your qualifications or a link to your LinkedIn Profile >

Checklist

• If my pull request is a new page, did I add that page to the _toc.yml file?
• Did I star the repo? ⭐️ (starring helps us attract more viewers and contributors!)
• Would I like my contribution to be featured on the @MakeUseofData Twitter account?
• Did I join the Discord

Twitter Username

< Replace this line with your Twitter username if applicable 😊 >

Thank you for your contribution! We look forward to including it in Data Science Notes