[alshdavid]

• Add .github/workflows/release.yaml to auto-increment the version, run test/format/lint/check, publish a GitHub release, and publish the crate to crates.io.
• Make file_server::create return crate::Result<HandleFunc>, precomputing the fallback extension once and propagating errors instead of panicking inside the handler.
• Reorganize file_server.rs into a file_server/ module with mod.rs, and reuse BODY_BUFFER_SIZE for the etag buffer.
• Update all examples to handle the new Result from create and pin the crate version to 0.0.0-local for release-time substitution.
• Note: publish_crates_io depends on a build job that does not exist in the workflow.