Add initial project structure with configuration, printing, and routing functionality

- Created a new Rust project with Cargo configuration.
- Added `.gitignore` to exclude target directory.
- Implemented `Cargo.lock` for dependency management.
- Defined application configuration in `config/app.yaml` and `src/config.rs`.
- Developed printing logic in `src/printer.rs` using `cups_rs` for printer interactions.
- Established routing and request handling in `src/routes.rs` for health checks and print requests.
- Introduced a scheduler in `src/scheduler.rs` to manage print job distribution.
- Created models for print parameters and job responses in `src/models.rs`.
- Set up the main application entry point in `src/main.rs` with server initialization and configuration loading.
- Included necessary dependencies in `Cargo.toml` for async handling, tracing, and configuration management.

Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "print-backend"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+anyhow = "1"
+async-trait = "0.1"
+axum = { version = "0.7", features = ["multipart", "json"] }
+base64 = "0.21"
+config = { version = "0.14", default-features = false, features = ["yaml"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+serde_yaml = "0.9"
+thiserror = "1"
+tokio = { version = "1", features = ["macros", "rt-multi-thread", "fs", "signal", "net"] }
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["fmt", "env-filter"] }
+tower-http = { version = "0.5", features = ["trace"] }
+cups_rs = "0.3"
+tempfile = "3"