set the workbench beta phase dates

Author: zkamvar

_config.yml

@@ -14,7 +14,10 @@ title: "Library Carpentry: The UNIX Shell"
 
 # Life cycle stage of the lesson
 # possible values: "pre-alpha", "alpha", "beta", "stable"
-life_cycle: "stable"
+life_cycle: "transition-step-1"
+transition_date_prebeta: '2022-12-12'
+transition_date_beta: '2023-02-06'
+transition_date_prerelease: '2023-04-03'
 
 
 #------------------------------------------------------------