[INFRA] add steps for release protocol (PDF upload)

[sappelhoff]

Adding the steps to be followed for uploading stable PDFs to Zenodo.

ticks off one more box of To Dos in #407 🙂

[franklin-feingold]

thanks @sappelhoff for adding this!

To confirm, the pdf extraction step (step 6) is that necessary before we can tag and publish a release? These aren't making commits so it doesn't appear so? If not, I'll suggest a small note to add to document that

[sappelhoff]

To confirm, the pdf extraction step (step 6) is that necessary before we can tag and publish a release?

the pdf must be extracted after the commit of setting the version to "stable" (i.e., removing -dev), and before any other commit, and I figured it'd be natural to do it as soon as possible to be sure :-)

[franklin-feingold]

that sounds good!