Update README

docs/install.md

 # Installation and configuration
 ## Requirements
-The system has been tested and found to run well on Ubuntu >= 18
-* The programming language is Python >= 3.6 
-* The web framework is currently [Django 3.1](https://docs.djangoproject.com/en/3.1/)
+The system has been tested and found to run well on Ubuntu >= 22
+* The programming language is Python >= 3.8 
+* The web framework is currently [Django 4.2](https://docs.djangoproject.com/en/4.2/)
 * Apache web server with mod_wsgi compiled for Python 3
+* memcached
 
 ## Install and setup
 1. Install and activate a virtual Python environment