Create swagger docs for all the backend REST API endpoints

MVP 3 - 6/28 - 7/12, MVP3 - 7/12 - 7/26, MVP3 - 7/26 - 8/9, MVP 3 - 8/9 - 8/23, MVP 3 - 8/23 - 8/30, Release 4 - 9/4 - 9/13, Release 4 - 9/13 - 9/27, Release 5 - 9/27 - 10/11, Release 5 - 10/11 - 10/25, Release 5: 11/1 to 11/15