Added override for environment

Chart/values.yaml

@@ -44,6 +44,9 @@ site:
   additional_env: {}
   #  MY_ENV_VAR: "value"
 
+  # Override the environment. Valid values are production, staging and development
+  # overrideEnvironment: "staging"
+
   # Create sites with another main domain for WP, 
   # but the rest of the components named according to site-tld 
   # overrideMainUrl: ""