Migrate projects, primers, and paths into the curriculum repo

[illicitonion]

We're both diversifying the content of the course (so "go" in the title isn't always relevant as other languages come in). We also want to take advantage of the work we've done in the curriculum repo. So we're going to move the content from this repo to https://github.com/CodeYourFuture/curriculum (keeping in place some redirects or references as we do)