docs: add tip for using fireEvent in Basic Example

[CamargoCode]

Tip on README.md code
What:

To give more explanation about the code
Why:

Using VS Code inserting a tip line
How:

Checklist:

• Documentation added to the
  docs site
• Tests
• TypeScript definitions updated
• [X ] Ready to be merged
  Yes

Added a short documentation tip in the Basic Example section of README.md to guide beginners on how to use fireEvent for user interactions.

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[CamargoCode]

Hi! I fixed the formatting issue as requested. I see that some CI builds are still failing, but it looks like they're unrelated to my docs-only change. Please let me know if anything else is needed!

[MatanBobi]

Hi.
Thanks for this proposal but I don't think it's needed, folks are usually using the testing-library.com site and even if they weren't, this example looks quite straightforwards to me.