Set up express server, connected to mongoDB and set up schema and basic router

[Jnwong116]

Changes

• Express server created
• Connected to MongoDB
• Set up user and nomination schema
• Created userRouter

Checklist

• [x] Pull request has descriptive context useful to reviewer. Screenshots are attached as necessary.
• [x] Pull request title matches Linear ticket.
• [x] Ticket has been claimed on Linear
• [x] Pull Request has been assigned to yourself
• [ ] Pull request has been approved by CodeOwner
• [ ] Pull request has been approved by one other student

[linear[bot]]

RUN-21 Record Backend/MongoDB Lesson