usb-device: Rename descriptor.append to extend.

Nitpicky change, but what it does is closer to the latter wrt bytearrays
and similar in Python.

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

micropython/usb/usb-device/usb/device/impl.py

@@ -164,14 +164,14 @@ class _Device:
         # Determine the total length of the configuration descriptor, by making dummy
         # calls to build the config descriptor
         desc = Descriptor(None)
-        desc.append(initial_cfg)
+        desc.extend(initial_cfg)
         for itf in itfs:
             itf.desc_cfg(desc, 0, 0, [])
 
         # Allocate the real Descriptor helper to write into it, starting
         # after the standard configuration descriptor
         desc = Descriptor(bytearray(desc.o))
-        desc.append(initial_cfg)
+        desc.extend(initial_cfg)
         for itf in itfs:
             itf.desc_cfg(desc, itf_num, ep_num, strs)
 
@@ -603,8 +603,8 @@ class Descriptor:
             struct.pack_into(fmt, self.b, offs, *args)
         self.o = max(self.o, end)
 
-    def append(self, a):
-        # Append some bytes-like data to the descriptor
+    def extend(self, a):
+        # Extend the descriptor with some bytes-like data
         if self.b:
             self.b[self.o : self.o + len(a)] = a
         self.o += len(a)