Comment support for tvgt

[mgord9518]

Although the documentation states tvgt is intended for debugging, it's also useful for creating "source code" for manually-optimized tvg images, and comments could be good for explaining what commands construct what area of the image

[ikskuh]

Sounds good. Accepted comment syntax is pascal comment syntax. It starts a comment with (* and ends it with *), no support for line comments.

(* this is my first TinyVG file! *)
(tvg 1
  (24 24 1/32 u8888 default)
  (
    (0.161 0.678 1.000)
    (1.000 0.945 0.910)
  )
  (
    (* empty for now *)
  )
)