feat: initialize codebase-to-prompt project with core functionality

- Added Cargo.toml for project dependencies and metadata.
- Implemented main library logic in src/lib.rs to process files in a directory.
- Introduced configuration struct to manage input parameters.
- Added command-line argument parsing in src/main.rs using clap.
- Implemented output formatting options (Markdown, Text, Console).
- Integrated tracing for logging and error handling.
- Added support for including/excluding file types and respecting .gitignore.

Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "codebase-to-prompt"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+anyhow = "1.0.99"
+chrono = "0.4.41"
+clap = { version = "4.5.45", features = ["derive"] }
+git2 = "0.20.2"
+ignore = "0.4.23"
+tracing = "0.1.41"
+tracing-subscriber = "0.3.19"
+walkdir = "2.5.0"