Merge branch 'release/0.6.0-alpha' into 'main'

app/Config/Developer.php

app/Config/Feature.php

app/Config/Routes.php

app/Config/Validation.php

app/Controllers/Activity.php

app/Controllers/BaseController.php

app/Controllers/Sport.php

app/Filters/AccessFilter.php

app/Libraries/DayConverter.php

app/Models/ActivityModel.php

app/Models/RegistrationModel.php

app/Models/SportModel.php

app/Models/UserModel.php

app/Validation/ActivityRules.php

app/Views/activity/_form.html

app/Views/activity/show.html

app/Views/sport/_form.html

app/Views/sport/index.html

app/Views/sport/show.html

app/Views/template.html