Fix digit colouring

[ideabucket]

In the README I wrote:

Digits in the manpage will also be coloured, because that's BBEdit's default behaviour when syntax-colouring is on. There doesn't appear to be any way to turn this off except by globally editing your colour scheme.

Actually it should be possible using some of the functionality documented in the BBEdit 11+ Language Module changes technote to disable this on a per-module basis, either by mucking about with Number Pattern or by redefining one of the RunKinds. At some point I'll look into this.