README: sort newest to oldest

Author: dlech

README.md

@@ -6,22 +6,22 @@ from [MicroPython](https://github.com/micropython/micropython) via PyPI.
 There are multiple MPY ABI versions, so you will need to install the package
 that corresponds to the target MicroPython version.
 
-For MicroPython 1.12 to 1.18:
+For MicroPython 1.23:
 
-    pip install mpy-cross-v5
+    pip install mpy-cross-v6.3
 
-For MicroPython 1.19:
+For MicroPython 1.22:
 
-    pip install mpy-cross-v6
+    pip install mpy-cross-v6.2
 
 For MicroPython 1.20 to 1.21:
 
     pip install mpy-cross-v6.1
 
-For MicroPython 1.22:
+For MicroPython 1.19:
 
-    pip install mpy-cross-v6.2
+    pip install mpy-cross-v6
 
-For MicroPython 1.23:
+For MicroPython 1.12 to 1.18:
 
-    pip install mpy-cross-v6.3
+    pip install mpy-cross-v5