Add section to examples docs with external examples

[nikolausWest]

There are a bunch of great external examples (not included in the Rerun repo) that are currently hard for users to find. We should add them all to the examples page.

This requires:

• Taking new screenshots
• Which in turn requires recording new rrd files for all the examples

Would be nice if:

• We could update these to use the new object oriented api's that are coming in 0.9

[nikolausWest]

External examples:

• https://github.com/rerun-io/tapnet
• https://github.com/rerun-io/point-shap-e
• https://github.com/rerun-io/limap
• https://github.com/rerun-io/simplerecon
• https://github.com/rerun-io/MCC
• https://github.com/rerun-io/slahmr
• https://github.com/rerun-io/grounding-sam
• https://github.com/rerun-io/differentiable-blocksworld

[roym899]

Closed by #3020