(gui) Make sensing "key pressed" block input droppable

src/lib/make-toolbox-xml.js

@@ -431,7 +431,11 @@ const sensing = function (isStage) {
         </block>
         <block id="answer" type="sensing_answer"/>
         ${blockSeparator}
-        <block type="sensing_keypressed"/>
+        <block type="sensing_keypressed">
+            <value name="KEY_OPTION">
+                <shadow type="sensing_keyoptions"/>
+            </value>
+        </block>
         <block type="sensing_mousedown"/>
         <block type="sensing_mousex"/>
         <block type="sensing_mousey"/>