🐛 Bug: Allcontributors table images should have loading=lazy

### Bug Report Checklist

- [X] I have tried restarting my IDE and the issue persists.
- [X] I have pulled the latest `main` branch of the repository.
- [X] I have [searched for related issues](https://github.com/JoshuaKGoldberg/create-typescript-app/issues?q=is%3Aissue) and found none that matched my issue.

### Expected

Images in the allcontributors table should have [`loading="lazy"`](https://developer.mozilla.org/en-US/docs/Web/Performance/Lazy_loading#images_and_iframes) so that they don't slow down initial page load or render.

### Actual

I tried loading https://github.com/JoshuaKGoldberg/create-typescript-app in a throttled network connection and noticed a lot of images loading right away. They even seemed to be blocking first page render Yuck.

### Additional Info

This might involve fixing on the allcontributors side?

I also don't know if this is possible in GitHub's markdown renderer... but it really should be. If it isn't, I should find a place to request it / upvote an existing request.