feat: read configs w/ tidy

Config files now use tidy::json::value and tidy::toml::value
instead of jsonc-parser and the toml crate. A config accepts
what the formatters accept, with one parser for each language,
and 10 crates leave the tree. Syntax errors give line:column.
Parse sizes its buffers from the text, so parse and conversion
are as fast as the crates were.