This improves our documentation on how to get started with design and
development tasks in the Fedora Badges project. It includes a section on
the things specific to Fedora Badges but also mentions the upstream
concentricsky/badgr-server project.

I added a note that these are specific to Outreachy Summer 2020, because
it is likely this section will need to change after Outreachy. But I am
erring on the side of being too detailed and risking it becoming
outdated, instead of not being detailed enough to direct people to the
right place.

Also I skimped on the sysadmin docs, but I want to move our sysadmin
docs out of the Fedora Infra SOP and into this repo so everything lives
in one place. Once it lives here, I'll update that section too.