[game] Do some amount of snapshot save and restore

This is super jankety and I feel the need for organization but FOR NOW
let's hack away.

game/main.ts

@@ -49,6 +49,20 @@ export function init() {
   load_assets();
 }
 
+export function suspend() {
+  return { clock };
+}
+
+export function resume(snapshot) {
+  if (snapshot) {
+    print("!Resuming!");
+    const { clock: new_clock } = snapshot;
+    if (new_clock) {
+      clock = new_clock;
+    }
+  }
+}
+
 const friction = 0.6;
 let robo_vel = new_v2(0);
 let robo_pos = new_v2(10);