reworked ParamSequence into Configuration

developement_help.md

@@ -1,6 +1,7 @@
 ## add parameter
 - add it to ```utils.parameters```
 - add it to README.md
-- add the necessary logic in the appropriate ```initialize:Config``` class
+- add the necessary Rules in ```utils.parameters```
 - optional : add a default value
 - optional : add to valid_variable
+- optional : add to mandatory_parameters