Update README.md

Author: rlwest

README.md

@@ -1,6 +1,8 @@
 # Python ACT-R
 A Python implementation of the ACT-R cognitive Architecture
 
+Please note that this version of Python ACT-R does not run on Python 3.11 or higher
+
 Install Python ACT-R from the command line using either `pip` or `pip3` as follows:
 
 ```bash