v1.2 - Folders, Subjects, Saved Studysets, & Better DevOps Automation Stuff

v1.2.0 adds folders and saved studysets so users can organize their studysets better, adds subjects to filter/organize & query public studysets better (which also replaces search queries), fixes deployment/devops scripts/stuff so now everything "just works" (DB and API-server) when deploying to production, and fixes a minor bug where Google OAuth full names were labelled as emails (very inconsequential and easily resolved issue, and because of our improved devops stuff, existing data "just works"/gets fixed with our automated database migration thingy using dbmate).