v0.0.14: Website, split Erlang library, proper exit codes, and better runtime support

Changelog

• erlang: the Erlang library included, with a lexer/parser/AST/printer
  for Standard Erlang, is now completely split from the Caramel code and
  will be published to opam shortly.

• caramelc: will return exit code 0 if everything went well. Otherwise
  expect a non-zero status!

• stdlib: remove dependency on the Erlang AST printer for parts of the
  runtime (like the recv function), and instead include the relevant
  .erl sources as part of the packed stdlib.

• docs: better contribution notes, documenting the release flow and
  saying a word about the rationale behind it. I've also put together a
  small website for Caramel here: https://caramel.abstractmachines.dev

• examples: the echo tcp server has been refactored to make it harder to
  accidentally override the gen_tcp module that is shipped with Erlang.
  We'll have to figure out a nice way to prevent these things from
  happening, which may just mean using all the modules on the Stdlib to
  avoid redefinition.

• ci: several changes to CI to ensure we can release the erlang
  library to opam.