Add welcome sound

src/hub.html

@@ -93,6 +93,7 @@
             <a-asset-item id="sound_asset-start_draw"                     src="./assets/sfx/PenDraw1.wav"     response-type="arraybuffer" preload="auto"></a-asset-item>
             <a-asset-item id="sound_asset-stop_draw"                      src="./assets/sfx/tap_mellow.wav" response-type="arraybuffer" preload="auto"></a-asset-item>
             <a-asset-item id="sound_asset-camera_tool_took_snapshot"      src="./assets/sfx/PicSnapHey.wav" response-type="arraybuffer" preload="auto"></a-asset-item>
+            <a-asset-item id="sound_asset-welcome"                        src="./assets/sfx/welcome.wav"     response-type="arraybuffer" preload="auto"></a-asset-item>
 
             <!-- Templates -->
             <template id="video-template">
@@ -475,6 +476,8 @@
                 scene-sound__cursor_distance_change_blocked="on: cursor-distance-change-blocked;"
                 sound__camera_tool_took_snapshot="positional: false; src: #sound_asset-camera_tool_took_snapshot; on: nothing; poolSize: 1;"
                 scene-sound__camera_tool_took_snapshot="on: camera_tool_took_snapshot;"
+                sound__welcome="positional: false; src: #sound_asset-welcome; on: nothing; poolSize: 2;"
+                scene-sound__welcome="on: entered;"
             >
                 <a-entity
                     id="gaze-teleport"