Updated README.md

Signed-off-by: VirtualTam <virtualtam@flibidi.org>
anthracite: a dark, low-contrast theme

Signed-off-by: VirtualTam <virtualtam@flibidi.org>
perfect-daark: cheat with style!

Signed-off-by: VirtualTam <virtualtam@flibidi.org>
zlib license added

Signed-off-by: VirtualTam <virtualtam@flibidi.org>