Implement USB HID Device Support for ESP32-S2 (#5538)

* Add support and example for USB HID Devices
* Add support and example for USB Vendor

libraries/USB/examples/Keyboard/KeyboardSerial/KeyboardSerial.ino

@@ -0,0 +1,40 @@
+/*
+  Keyboard test
+
+  Reads a byte from the serial port, sends a keystroke back.
+  The sent keystroke is one higher than what's received, e.g. if you send a,
+  you get b, send A you get B, and so forth.
+
+  The circuit:
+  - none
+
+  created 21 Oct 2011
+  modified 27 Mar 2012
+  by Tom Igoe
+
+  This example code is in the public domain.
+
+  http://www.arduino.cc/en/Tutorial/KeyboardSerial
+*/
+
+#include "USB.h"
+#include "USBHIDKeyboard.h"
+USBHIDKeyboard Keyboard;
+
+void setup() {
+  // open the serial port:
+  Serial.begin(115200);
+  // initialize control over the keyboard:
+  Keyboard.begin();
+  USB.begin();
+}
+
+void loop() {
+  // check for incoming serial data:
+  if (Serial.available() > 0) {
+    // read incoming serial data:
+    char inChar = Serial.read();
+    // Type the next ASCII value from what you received:
+    Keyboard.write(inChar + 1);
+  }
+}