Create a `bevy_examples` crate that includes bevy as a dependency

We should just create the crate so we can agree on the structure / placement of this crate within the project before proceeding with starting to migrate a single example.

Blocks all other work in #25328

Review the repository's existing crate layout and workspace configuration to determine where the new bevy_examples crate belongs and how it should depend on bevy. Done means the crate exists in the agreed location with the dependency configured, establishing the structure needed for the example migration in #25328.

Written by the indexing model from the issue text.