add css file
add content in activity_page
change route
add ActivityListController
write activity_list_page
write ActivityListController
add create_activity_page
change route
add CreateActivityController
change pages/create_activity to pages/create_activity_page
modified create_activity_page
write CreateActivityController
add route "/activity_list"
Perfect create_activity_page
add a Activity model
add save_to_localStorage for Activity model
done activity create and list
add save_all_activities_name for Activity
rename function for Activity
add judge_activity_name