Add "MACVIM REFERENCE" to syntax rule to reflect the new header to make
it look less weird. Also remove the "last changed date" header since I
rarely update it and it's not particularly useful given how in MacVim
the runtime is always bundled anyway.
Also, when investigating using Neovim's treesitter vim docs generating
tool for MacVim (to generate a web version of the documentation), found
a few typos / formatting issues. Fix them here.
9bf55ef10d
