Greyscale or colour-blindness PDF converters in https://typst.app/tools/

[patrick-kidger]

I can see that https://typst.app/tools/ has some nice tools, presumably to broaden the top-of-funnel marketing :)

To that end, a couple of tools that I've just found myself needing, and thought might be a good fit, are:

• A PDF converter to make it greyscale, to check how a PDF will appear on e-ink readers.
• A PDF converter to simulate various kinds of colour-blindness, to check that a PDF is suitably accessible.