Fix validate_batch target squeeze (#3033)
Fix validate_batch target squeeze (#3033)

* Modefied the quickstart page of Orca

* Add 'zoo' to 'analytics'

* Fix some small typoes

* Alignment

* fix validate_batch() issues: 1. target size does not match the size of output when doing criterion. 2. loss is not averaged?

* undo comment

* fix indentation issue

* remove debug codes
intel-analytics/analytics-zoo,intel-analytics/analytics-zoo,intel-analytics/analytics-zoo