clarify applet logic

island.ts

@@ -195,6 +195,13 @@ function renderIslands(islands: IslandGrid, cx: CanvasRenderingContext2D) {
 }
 
 export function IslandApplet() {
+  // STATE
+
+  let timerId: number;
+  let islands = new IslandGrid(WIDTH, HEIGHT, DEFAULT_SEED);
+
+  // UI
+
   const [canvas, cx] = canvas2d({
     width: WIDTH * BLOWUP,
     height: HEIGHT * BLOWUP,
@@ -203,14 +210,6 @@ export function IslandApplet() {
 
   const seedInput = h("input", { type: "number", valueAsNumber: DEFAULT_SEED });
   const seedLabel = h("label", {}, "Seed:", seedInput);
-
-  // STATE
-
-  let timerId: number;
-  let islands = new IslandGrid(WIDTH, HEIGHT, DEFAULT_SEED);
-
-  // CONTROLS
-
   const generateButton = h(
     "button",
     {