fix: cleanup to comply with joj features

JOJ3-Configuration-Schema.md

@@ -7,7 +7,8 @@ Levels:
 - assignment: eg. homework or project
 - task: eg. exercise or milestone
 
-A task is composed of *stages* which themselves are composed of one or more *steps*.
+A task is composed of *stages* which themselves might be composed of one or more *steps*, eg. for
+the stage "online-judge" each test-case can be viewed as a step.
 
 ## Background 
 
@@ -136,6 +137,8 @@ Some parsers can also be further configured.
 # general task configuration
 task="Homework 1 exercise 2" # used for "comment" field in "json" config file
 stages = [ "compile", "code-quality", "judge-base", "judge-msan" ] # list of stages, can feature a unique stage
+deadline = 2024-10-12T23:59:00+08:00
+
 
 [compile]
 command = "cmake"