add option to turn on access log

ab-nginx.params.template

@@ -1,7 +1,7 @@
 #####
 # Parameters for use by ab-nginx convenience script
 #
-# NOTE: 'TRUE' and 'FALSE' MUST BE IN CAPITALS!
+# NOTE: 'TRUE', 'FALSE', 'ON' and 'OFF' MUST be in all CAPITALS!
 #
 # If you are not using the 'ab-nginx.sh' script file to start the container,
 # then you don't have to do anything with this file.
@@ -34,6 +34,11 @@ SERVER_NAMES="domain.tld www.domain.tld server.domain.tld alt.domain.tld"
 HTTP_PORT=80
 HTTPS_PORT=443
 
+# Access logging (global preference):
+# Unless overridden in a server/location block, access logging will be handled 
+# according to this setting.  Default is OFF.  Choices are 'ON' or 'OFF'.  Logs 
+# will be printed to the console so they are accessible via 'docker logs ...'
+ACCESS_LOG=OFF
 
 ### Content files
 # Whatever you specify here will replace the default files in the container