fix: adjust dead documentation link

[ThomasMinor]

Summary

Fix a dead documentation link, the puppetlabs.github.io pages seem to be gone.

[CLAassistant]

All committers have signed the CLA.

[ThomasMinor]

It seems the link is still broken, will the content be available at some time?
If yes, this PR could be closed.

[ThomasMinor]

Hi @ekohl, @bastelfreak, @smortex,
the link is still broken. If it will be fixed sometime we can close this PR, otherwise think about approving it.

[smortex]

@ThomasMinor this is currently an issue with all puppetlabs module. I asked on slack if this file is managed automatically from some internal tooling (it does not seems to be managed from pdk-templates) or if opening one PR / repo make sense but got no answer. I pinged them again.

AFAIAC, this new URL in this PR is fine, and if we have no news from people at puppetlabs, I am fine with replacing this broken link with a working one with similar content like this one.

[ThomasMinor]

Any News on this topic?

[ekohl]

@ThomasMinor you're pinging the non-Perforce people but IMHO they are responsible for the CONTRIBUTING.md file. Given their recent blog post I'm not sure if they actually want people to contribute at all so I'm not going to be helpful here.