Update enum support (No - need metaclasses)

Standard-Library-Coverage.md

@@ -70,7 +70,7 @@
 | [encodings.mbcs](https://docs.python.org/3/library/codecs.html#module-encodings.mbcs) |  Windows ANSI codepage | ? | 
 | [encodings.utf_8_sig](https://docs.python.org/3/library/codecs.html#module-encodings.utf_8_sig) |  UTF-8 codec with BOM signature | ? | 
 | [ensurepip](https://docs.python.org/3/library/ensurepip.html#module-ensurepip) |  Bootstrapping the "pip" installer into an existing Python installation or virtual environment. | ? | 
-| [enum](https://docs.python.org/3/library/enum.html#module-enum) |  Implementation of an enumeration class. | ? | 
+| [enum](https://docs.python.org/3/library/enum.html#module-enum) |  Implementation of an enumeration class. | ❌ | Metaclasses are not yet supported in MicroPython and it's challenging to provide enum support without it. 
 | [errno](https://docs.python.org/3/library/errno.html#module-errno) |  Standard errno system symbols. | ✅ | [built-in](https://docs.micropython.org/en/latest/library/errno.html) and [micropython-lib](https://github.com/micropython/micropython-lib/tree/master/python-stdlib/errno)
 | [faulthandler](https://docs.python.org/3/library/faulthandler.html#module-faulthandler) |  Dump the Python traceback. | ? | 
 | [fcntl](https://docs.python.org/3/library/fcntl.html#module-fcntl) |  The fcntl() and ioctl() system calls. | ? |