…lizations do not become stale or broken.

Add a README for documenting how the debugger visualizers and how to embed/ test them.
Update the github actions CI workflow to manually enable features, in addition to the default features, to allow for testing unstable features separately.

Cleanup running tests with the serde feature enabled.

Update documentation noting the debugger_visualizer crate feature is an unstable feature.

Respond to PR comments. Fix unused variables warnings.

Fix lint errors

Enable features via `member:feature` syntax.

… names in the Rust compiler.