* Update dependencies
* Document the lexer and lightly improve its names
The bulk of this pull request adds a substantial amount of new inline
documentation for the lexer. Along the way, I made a few minor changes
to the names in the lexer, most of which were internal.
The main change that affects other files is renaming `group` to `block`,
since the function is actually parsing a block (a list of groups).
* Fix rustfmt
* Update lock
Co-authored-by: Jonathan Turner <jonathandturner@users.noreply.github.com>
Co-authored-by: Jonathan Turner <jonathan.d.turner@gmail.com>