Redirecttousb (#604)

* add block to redirect back to USB

* added docs

* bump minor version

libs/core/shims.d.ts

@@ -831,8 +831,16 @@ declare namespace serial {
     //% tx.fieldEditor="gridpicker" tx.fieldOptions.columns=3
     //% tx.fieldOptions.tooltips="false"
     //% rx.fieldEditor="gridpicker" rx.fieldOptions.columns=3
-    //% rx.fieldOptions.tooltips="false" shim=serial::redirect
+    //% rx.fieldOptions.tooltips="false"
+    //% blockGap=8 shim=serial::redirect
     function redirect(tx: SerialPin, rx: SerialPin, rate: BaudRate): void;
+
+    /**
+     * Redirects the serial instance to USBTX and USBRX.
+     */
+    //% weight=9 help=serial/redirect-to-usb
+    //% blockId=serial_redirect_to_usb block="serial|redirect to USB" shim=serial::redirectToUSB
+    function redirectToUSB(): void;
 }