Document admin process for launching a new tutorial

Need to document steps a maintainer/admin needs to do or coordinate each time a PR for a new tutorial is submitted. Would including things like:

In the tutorial PR, before merging:

[ ] Copy edit for grammar and clarity
[ ] Technical review from an SME for accuracy
[ ] Create a social tile for new tutorial
[ ] Determine whether a new project logo is needed
[ ] Determine whether a new course is needed and add if required, including description, SEO description, and other tutorials to include
[ ] Determine which existing courses we to add this tutorial to (should almost always be in featured at launch)
[ ] Determine for which other courses this tutorial should be added to the resources page
[ ] Review suggested resources being linked to, ensure they're relevant and appropriately labelled, add more as needed, including any existing ProtoSchool tutorials that make sense as a follow-on
[ ] Condense images

Outside of this PR:

[ ] find places on relevant project websites, GH repos, docs, etc. where it makes sense to link to this tutorial
[ ] draft a blog post for most appropriate project blog
[ ] draft an email announcement in Mailchimp
[ ] schedule social media posts including things like:
- [ ] we have a new tutorial on x coming soon, sign up for the newsletter to be the first to know when it's published
- [ ] announcement linking to blog post
- [ ] announcement linking to new tutorial
- [ ] announcement highlighting course the new tutorial is contained in
[ ] get relevant projects to retweet
[ ] update workshop submission form to include new tutorial

@zebateira please feel free to edit the list above to add more detail or additional suggestions

ProtoSchool / protoschool.github.io