Upgrade example documentation

[nikolausWest]

Many people learn best from studying examples, but our documentation around our examples is currently sub-par. We need to make it much easier to find the most helpful example and make the documentation easier to maintain.

Roughly prioritized high to low:

• Make the landing of https://www.rerun.io/examples more interesting (screenshots, links, or just land on https://www.rerun.io/examples/real-data)
• Make the written content and structure of the examples page more compelling
• Add section to examples docs with external examples #2928
• Improve example naming #2259
• Reorganize example docs structure #2267
• Unify example documentation with the examples README(s) #2268
• Categorize examples by tags #2270
• Filter examples by tags on the docs site #2272
• Add command to screenshot the whole viewer #2117
• Unify screenshots in docs
• Unify example screenshots #2273
• Ensure images in docs don't merge into the background #2399
• Make it easier to find the API docs for Python and Rust
• Add an example template #2313
• All example screenshots should have alt-texts
• Docs site shows what rerun api's are used in each example
• Examples docs shows live web viewer where possible

[emilk]

It's high priority to work on these issues, but not high priority to close every single on of them. Let's start with the low hanging fruit

[nikolausWest]

Closing this issue and moving the remaining pieces we want to do to to a new tracking issue