Add a lexing-based 'highlight' mode to the parser

basic syntax highlighting

added more syntax highlighting coverage

add example of a markdown table with styling

move FIXED_TOKEN logic into highlight

refactor highlight, add support for backpassing

escape html from source code

fix bug with <pre> tag ordering

refactor out html from roc_parse

remove test, put highlight functionality into separate file

fix typo

crates/compiler/parse/src/lib.rs

@@ -10,6 +10,7 @@ pub mod ast;
 pub mod blankspace;
 pub mod expr;
 pub mod header;
+pub mod highlight;
 pub mod ident;
 pub mod keyword;
 pub mod module;