[website] Adds Kenan Yusuf to about page

[kenanyusuf]

Adding myself to the about page

• [x] I have followed (at least) the PR section of the contributing guide.

Preview: https://deploy-preview-42317--material-ui.netlify.app/about/

[mui-bot]

Netlify deploy preview

https://deploy-preview-42317--material-ui.netlify.app/

Bundle size report

No bundle size changes (Toolpad) No bundle size changes

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