Add workflow_run condition to documentation (close #64)

[danielvartan]

Related to #64.

Cheers!

[mpadge]

Thanks, but could you please modify in these ways:

• We can't have the workflow cancel when previous workflow failed, for the 2 reasons that (1) pkgcheck is intended to report workflow failures, so actually needs to be run on genuine failures; and (2) I think that will lead to an eternal cancel cycle that will fail first, then eternally detect previous fail and never work
• Please reduce the rather large code chunk to the minimal bits that could be added to make running conditional on finishing rcmdcheck workflow only, without the duplicated other bits?

I think that will effectively reduce the code to just your header section, but you'd also need to expand that to show how to add your condition while also keeping the previous on condition of being triggered on every push-to-main event 👍

[danielvartan]

Thanks for your revision, @mpadge.

I've made all the changes you requested. Please let me know if everything looks good.

[mpadge]

Thanks @danielvartan!