Scheduler docs links needs to be updated as per latest location

[LalatenduMohanty]

Scheduler docs has changed location to [2]. So [1] is giving 404 Page not found error.

[1] https://github.com/kubernetes/community/blob/master/contributors/devel/scheduler.md [2] https://github.com/kubernetes/community/blob/master/contributors/devel/sig-scheduling/scheduler.md