Implement Misses DSL compiler (parser + codegen)

- ast.rs: Full AST for .mrs files (MacroDef, Pattern, OutputBody, TemplateItem)
- parser.rs: Hand-written recursive descent parser with line/col error reporting
- codegen.rs: Transforms AST to Rust proc macro code using syn/quote/proc_macro2
- main.rs: CLI reads .mrs file, runs parse→codegen, writes to stdout or file
- Cargo.toml: Workspace with syn, quote, proc-macro2, prettyplease deps
- examples/: hello.mrs, derive_builder.mrs, declare_table.mrs reference examples

All three reference examples parse and produce prettyplease-formatted Rust output.
Generated code uses syn::parse::Parser closures for structural patterns, quote!
for token templates, spread iteration via .iter().map().collect(), and
format_ident! for identifier construction.

https://claude.ai/code/session_01Tppkab4eLsL21asHGjQJoF

.gitignore

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