Initialize Rust implementation of Lox interpreter

This initial commit sets up the basic structure for a Rust
implementation of the Lox interpreter, including:

- Lexer for tokenizing source code - Parser for building AST - Basic
interpreter functionality - Environment for variable storage

The core components include source tracking, error handling, and basic
expression evaluation.

.gitignore

@@ -0,0 +1,28 @@
+/target
+
+# Created by https://www.toptal.com/developers/gitignore/api/rust,rust-analyzer
+# Edit at https://www.toptal.com/developers/gitignore?templates=rust,rust-analyzer
+
+### Rust ###
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Remove Cargo.lock from gitignore if creating an executable, leave it for libraries
+# More information here https://doc.rust-lang.org/cargo/guide/cargo-toml-vs-cargo-lock.html
+Cargo.lock
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+### rust-analyzer ###
+# Can be generated by other build systems other than cargo (ex: bazelbuild/rust_rules)
+rust-project.json
+
+
+# End of https://www.toptal.com/developers/gitignore/api/rust,rust-analyzer
+.zed/