docs/library: Update machine.USBDevice documentation.

- Add stm32 (with TinyUSB) to list of supported ports
- Add example showing how to query current USB class configuration
  using bitwise AND and equality operations
- Update PR_DRAFT.md with combined class examples and query patterns

Demonstrates checking individual class enablement (& operator) and
exact configuration matching (== operator) for USB builtin_driver flags.

Signed-off-by: Andrew Leech <[email protected]>

Author: pi-anl

PR_DRAFT.md

@@ -8,8 +8,15 @@ Adds USB device class selection via `machine.USBDevice` API when using TinyUSB.
 import machine
 
 usb = machine.USBDevice()
-usb.builtin_driver = usb.BUILTIN_CDC  # Only CDC, no MSC
+usb.builtin_driver = usb.BUILTIN_CDC  # Only CDC
+usb.builtin_driver = usb.BUILTIN_CDC | usb.BUILTIN_MSC  # Both CDC and MSC
 usb.active(True)
+
+# Query current configuration
+if usb.builtin_driver & usb.BUILTIN_CDC:
+    print("CDC enabled")
+if usb.builtin_driver == (usb.BUILTIN_CDC | usb.BUILTIN_MSC):
+    print("Both CDC and MSC enabled")
 ```
 
 Works in both runtime mode (full dynamic USB support) and static mode (basic class control only). USB classes remain compiled but only enabled drivers appear in descriptors and enumerate with the host.

docs/library/machine.USBDevice.rst

@@ -4,9 +4,9 @@
 class USBDevice -- USB Device driver
 ====================================
 
-.. note:: ``machine.USBDevice`` is currently only supported for esp32, rp2 and
-          samd ports. Native USB support is also required, and not every board
-          supports native USB.
+.. note:: ``machine.USBDevice`` is currently only supported for esp32, rp2,
+          samd, and stm32 (with TinyUSB) ports. Native USB support is also
+          required, and not every board supports native USB.
 
 USBDevice provides a low-level Python API for implementing USB device functions using
 Python code. This includes both runtime device descriptor configuration and
@@ -390,6 +390,26 @@ Usage Examples
     usb.builtin_driver = usb.BUILTIN_CDC | usb.BUILTIN_NCM
     usb.active(True)
 
+**Querying Current Configuration:**
+::
+
+    import machine
+
+    usb = machine.USBDevice()
+    usb.active(False)
+    usb.builtin_driver = usb.BUILTIN_CDC | usb.BUILTIN_MSC
+    usb.active(True)
+
+    # Check if specific class is enabled using bitwise AND
+    if usb.builtin_driver & usb.BUILTIN_CDC:
+        print("CDC is enabled")
+    if usb.builtin_driver & usb.BUILTIN_MSC:
+        print("MSC is enabled")
+
+    # Check for exact configuration using equality
+    if usb.builtin_driver == (usb.BUILTIN_CDC | usb.BUILTIN_MSC):
+        print("Both CDC and MSC are enabled")
+
 **Switching Configurations at Runtime:**
 ::