Maintainance check-in

[carlosjeurissen]

The package seems to be in need for a postcss upgrade, considering warnings like:

css-colorguard: postcss.plugin was deprecated. Migration guide:
https://evilmartians.com/chronicles/postcss-8-plugin-migration

In addition, we have an open pull request:
#34

Since this package is being relied on, can we work towards doing a few quick updates, adding additional collaborators, or figure some way we can keep colorguard alive.

[jonasdk]

Any news on the update status on this project - this issue seems pretty old for a security issue.

[carlosjeurissen]

@bryanjtc Seems you took over development. Is there a specific page on which we can report issues like this one?
ierhyna/stylelint-no-indistinguishable-colors#19