Hack Tree-Sitters HTML Debug Output To Dark Mode

I'm working on a Tree-Sitter^ts^^ parser for Neopolitan. I'm using the `-D`` flag for command line tests to produce a `log.html`` file with a visual graph of the output. It's easier to figure out what's going on when things aren't going right.

The graph is produced by graphviz^gv^^ via an internal call STDIN call. The output is black text on a white background. As someone who like working in dark mode it's a bit of a flash-bang every time I switch to it.

To fix that, I pulled down the source code^sc^^ and made the following edits:

Add this to the style sheet section