Add start of ship rendering

js/world/index.mjs

@@ -1,3 +1,26 @@
 import * as sector from './sector.mjs';
+import * as spawn from './spawn.mjs';
 
 export {getSectorFromWorld, getContainedSectors} from './sector.mjs';
+
+export const entities = new Set();
+export const celestials = new Set();
+export const ships = new Set();
+
+export let playerShip = null;
+
+export function setPlayerShip(ship) {
+	playerShip = ship;
+}
+
+export function init() {
+	entities.clear();
+	celestials.clear();
+	spawn.player();
+}
+
+export function tick() {
+	celestials.forEach(c => c.tick());
+	entities.forEach(e => e.tick());
+	ships.forEach(s => s.tick());
+}