Apply suggestions from code review

Co-authored-by: Xiaoji Chen <Pessimistress@users.noreply.github.com>

Author: tordans

examples/get-started/hook/controls.jsx

@@ -7,24 +7,20 @@ export default function Controls() {
   /**
    * ## This is how `useMap` works:
    * ```
-   * const demo = useMap();
-   * console.log('Controls', {demo});
+   * const maps = useMap();
+   * console.log('Controls useMap()', maps);
    * ```
    * ### First render:
    * ```
    * {
-   *     "demo": {
-   *         "current": undefined
-   *     }
+   *     "current": undefined
    * }
    * ```
    * ### Second render:
    * ```
    * {
-   *   "demo": {
    *     "current": undefined,
    *     "mymap": {...} // See https://visgl.github.io/react-map-gl/docs/api-reference/types#mapref
-   *   }
    * }
    * ```
    */

examples/get-started/hook/controls2.js

@@ -8,16 +8,14 @@ export default function Controls2() {
    * See https://visgl.github.io/react-map-gl/docs/api-reference/use-map
    * See https://visgl.github.io/react-map-gl/docs/api-reference/types#mapref
    * ```
-   * const demo = useMap();
-   * console.log('Controls2', {demo});
+   * const maps = useMap();
+   * console.log('Controls2 useMap()', maps);
    * ```
    * ### First render:
    * ```
    * {
-   *     "demo": {
-   *       "current": {...},
-   *       "mymap": {...}
-   *     }
+   *     "current": {...}, // this is the same as `mymap`
+   *     "mymap": {...}
    * }
    * ```
    */

examples/get-started/hook/map.jsx

@@ -10,22 +10,18 @@ export default function MapView() {
   /**
    * ## This is how `useMap` works:
    * ```
-   * const demo = useMap();
-   * console.log('MapView', {demo});
+   * const maps = useMap();
+   * console.log('MapView useMap()', maps);
    * ```
    * ### First render:
    * ```
    * {
-   *     "demo": {
-   *         "current": undefined
-   *     }
+   *     "current": undefined
    * }
    * Second render:
    * {
-   *     "demo": {
-   *         "current": undefined,
-   *         "mymap": {...} // See https://visgl.github.io/react-map-gl/docs/api-reference/types#mapref
-   *     }
+   *     "current": undefined,
+   *     "mymap": {...} // See https://visgl.github.io/react-map-gl/docs/api-reference/types#mapref
    * }
    * ```
    */