Prework Milestone 2: Joining the server

**Problem:**
We cannot join the game server

**Issue Recreation Steps:**
- Fork repository
- Clone repository locally

**Implementation Suggestions:**
This is blocked by #8 so that should probably be handled first.

In the README, it says that we send a join game message, and the server will give us a player id, an avatar, and a random starting position, and the list of all current player positions and avatar images.

For this milestone, I just want to display my own avatar, named “Tim”. Avatars should have a label for their username.

My avatar should be in the middle of the browser window. Based on that centering, we should shift the viewport. However, don’t show past the edge of the map.

The avatar should be rendered using the images returned from the server, respecting aspect ratio and size, and drawing should be efficient to display many players.

**Testing Criteria:**
Open index.html and verify that you can see your avatar centered on the screen. Try reloading, your starting position should change with each reload.