Add 'showPorts' api doc (#392)

docs/SUMMARY.md

@@ -57,6 +57,7 @@
         * [show mood](/reference/brick/show-mood)
         * [show image](/reference/brick/show-image)
         * [clear screen](/reference/brick/clear-screen)
+        * [show ports](/reference/brick/show-ports)
         * [on event](/reference/brick/button/on-event)
         * [is pressed](/reference/brick/button/is-pressed)
         * [was pressed](/reference/brick/button/was-pressed)

docs/reference/brick.md

@@ -9,6 +9,7 @@ brick.showString("Hello world!", 1);
 brick.showNumber(0, 1);
 brick.showValue("item", 0, 1);
 brick.clearScreen();
+brick.showPorts();
 ```
 
 ## Buttons

docs/reference/brick/show-ports.md

@@ -0,0 +1,24 @@
+# show Ports
+
+Show the status of everything connected to the ports.
+
+```sig
+brick.showPorts()
+```
+
+You can find out what's connected to the ports on the brick and show its status. The status information from each sensor or motor connected is displayed on the screen.
+
+## Example
+
+Show the status of the ports on the brick when the ``enter`` button is pressed.
+
+```blocks
+brick.showString("Press ENTER for port status", 1)
+brick.buttonEnter.onEvent(ButtonEvent.Pressed, function () {
+    brick.showPorts()
+})
+```
+
+## See also
+
+[show string](/reference/brick/show-string), [show value](/reference/brick/show-value)