~jack/misc

misc/lambda-c d---------
lambda-c: add shell.nix
lambda-c: parse STLC typedecls in lambdas
lambda-c: use custom refcount type instead of grefcount
lambda-c: make the pretty printer not suck
lambda-c: fix the parser
lambda-c: fix gitignore
lambda-c: unbreak ci
lambda-c: lexer, broken parser
lambda-c: nix
lambda-c: Capture-avoiding substitution
lambda-c: dinky little evaluator