Optimizing 18 images - 12.51 MiB reduction (#6429)

This PR optimize the site images, using lossy algorithm. I did one of these in the past (#5349).


You might want to consider using the tool (https://www.shrink.sh) I used to generate this PR. Disclaimer, I am the author, and I wrote it exactly to solve this problem: it is too easy to forget the optimize images. The tool is triggered when new images are pushed on the master branch of a repo. Rebasing my fork with upstream triggered it.


Below is the PR description generated by the tool.

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# 🤖 Reduce image sizes by 49%!



### Optimized Images
#| 📁  File     | Original Size | New Size      | Savings
-|--------------|---------------|---------------|--------------
✅ | 16-snapshots.png | 150.10 KiB | 142.55 KiB | -5%
✅ | interactiveSnapshot.png | 128.66 KiB | 109.02 KiB | -15%
✅ | interactiveSnapshotUpdate.gif | 805.99 KiB | 511.21 KiB | -36%
✅ | interactiveSnapshotDone.png | 33.09 KiB | 28.03 KiB | -15%
✅ | airbnb.png | 51.70 KiB | 31.84 KiB | -38%
✅ | default-demo.gif | 7.25 MiB | 3.82 MiB | -47%
✅ | describe-demo.gif | 5.26 MiB | 2.48 MiB | -52%
✅ | tagged-template-literal.gif | 4.12 MiB | 1.41 MiB | -65%
✅ | test-demo.gif | 4.52 MiB | 2.23 MiB | -50%
✅ | 23-asymmetric-matchers.png | 265.32 KiB | 148.20 KiB | -44%
✅ | 23-async-matchers.png | 179.54 KiB | 99.34 KiB | -44%
✅ | 23-hanging-after.png | 233.85 KiB | 144.74 KiB | -38%
✅ | 23-hanging-before.png | 190.30 KiB | 117.83 KiB | -38%
✅ | 23-interactive.gif | 824.47 KiB | 655.32 KiB | -20%
✅ | 23-jest-each.png | 235.91 KiB | 129.32 KiB | -45%
✅ | 23-new-matchers.png | 295.07 KiB | 167.39 KiB | -43%
✅ | 23-snapshot-matchers.png | 344.73 KiB | 246.78 KiB | -28%
✅ | 23-typeahead.gif | 308.19 KiB | 181.83 KiB | -40%
🍪|**Total**| 25.11 MiB | 12.59 MiB | -49%