add lexer

The lexer parses incoming code into tokens, which makes it simpler to
process using `chumsky`.

Author: gerau

Cargo.lock

@@ -33,6 +33,7 @@ either = "1.12.0"
 itertools = "0.13.0"
 arbitrary = { version = "1", optional = true, features = ["derive"] }
 clap = "4.5.37"
+chumsky = "0.11.2"
 
 [target.wasm32-unknown-unknown.dependencies]
 getrandom = { version = "0.2", features = ["js"] }