Add clear button to handwriging

handwriting/handwritingui/main.qml

@@ -66,6 +66,21 @@ ApplicationWindow {
                     }
                 }
             }
+
+            Connections {
+                target: clearButton
+                onClicked: {
+                    tile.color = "black"
+                }
+            }
+        }
+    }
+
+    Column {
+        anchors.right: parent.right
+        Button {
+            id: clearButton
+            text: "Clear"
         }
     }
 }