docs(README): add 'toss' logo image

[sukvvon]

Overview

Checklist

• Did you write the test code?
• Have you run yarn run fix to format and lint the code and docs?
• Have you run yarn run test:coverage to make sure there is no uncovered line?
• Did you write the JSDoc?

[kimyouknow]

@sukvvon Hi, thank you for your contribution!

This PR currently has conflicts with the main branch. Could you please rebase on the latest main and resolve the conflicts?

Note: We've recently restructured the project (#329) — react-simplikit now focuses on platform-independent hooks. We've also introduced @react-simplikit/mobile for mobile web-specific challenges (viewport, keyboard, layout on iOS Safari/Android Chrome).

[sukvvon]

@kimyouknow Thank you for the review and for letting me know about the restructuring!

I've rebased on the latest main and resolved the conflicts. The Toss logo has been added to the updated README.md that reflects the new monorepo structure with react-simplikit and @react-simplikit/mobile.

Please let me know if there's anything else that needs to be adjusted!

[kimyouknow]

Thanks! LGTM!