Elixir NIFs to TreeSitter - session 6: Multi-language Parsers / BONUS: Hardhat 1.0 Release

We return to our NIF for Tree-Sitter, unifying the functions that parse and re-parse a document into a single function, and then adding the APIs needed to support multi-language documents (like embedded templates). We finish off the stream with finishing one feature and some documentation on the Hardhat HTTP client, bumping the version to 1.0!