Prepare Rust SDK agent examples and docs for 0.2.0

[NicholasDCole]

This PR does 2 things:

1. examples runnable via simple run-arg to configure model .
2. docs updated to be more readable to human looking for how to run conductor-agents

Test Evidence:

Examples running via command args/env vars

Commands

Execution Ran in UI

[NicholasDCole]

Closing this draft PR; the requested deliverable is a local feature branch only.

[propp-orkes]

I think this is a really good clarification and update for our examples and documentation. I've highlighted one place that might be a bug, but overall this looks solid. I think the choice to remove the examples/support/mod.rs and bring that into each example so they can stand alone is the correct one. I recognize the porting behavior did that to prevent redundancy, but at the cost of readability, which is the point.

[chrishagglund-ship-it]

Seems the changelog is losing some info about the breaking changes that were made which could be useful for upgraders - was that intentional?

Will keep an eye out for the 0.2.0 switch, I think the number needs to be updated in 2x Cargo.toml files and then several .md files to match