Adding shadow block to serial write buffer (#1111)

libs/core/serial.cpp

@@ -113,7 +113,7 @@ namespace serial {
     /**
     * Send a buffer through serial connection
     */
-    //% blockId=serial_writebuffer block="serial|write buffer %buffer"
+    //% blockId=serial_writebuffer block="serial|write buffer %buffer=serial_readbuffer"
     //% help=serial/write-buffer advanced=true weight=6
     void writeBuffer(Buffer buffer) {
       if (!buffer) return;

libs/core/shims.d.ts

@@ -799,7 +799,7 @@ declare namespace serial {
     /**
      * Send a buffer through serial connection
      */
-    //% blockId=serial_writebuffer block="serial|write buffer %buffer"
+    //% blockId=serial_writebuffer block="serial|write buffer %buffer=serial_readbuffer"
     //% help=serial/write-buffer advanced=true weight=6 shim=serial::writeBuffer
     function writeBuffer(buffer: Buffer): void;