cherry pick 2544, add formula for entropy and kl-divergence in Uniform and Normal classes (#2544) (#2616)

* add formula for entropy and kl-divergence

* fix formula in cn doc

* fix formula for Normal

* fix_hapi_path for 2.0-beta

* fix alias

* add paddle.io. test=develop

* fix indent. test=develop

* fix tutorial test=develop

* fix pic test=develop

* update tutorial test=develop

* remove alias test=develop

* remove api_attr

* add_apis_and_fix_alias

* fix code bugs

* fix___init_bug

* fix migration guide

* add api_reference test=develop

* fix style test=develop

* change faq to chinese test=develop

* add release note en

* fix release note test=develop

* fix api_reference test=develop

* fix style test=develop

* add input_spec cn

* add input_spec cn

* fix === style

* fix file name typo

* add ref

* add en doc

* fix en doc

* refine according reviewer

* remove user comment

* refine doc

* refine doc

* add paddle.vision.transforms.* api cn doc

* add alias for paddle.vision.transforms

* delete invalid file

* add some empty doc file for rd

* delete some text alias

* change some doc path

* add some hapi cn docs

* Add English doc of debugging

* Add English doc of error_handling

* add release note

* fix_style

* fix_style

* remove @name test=develop

* add paddle.vision.transforms.* api cn doc

* add alias for paddle.vision.transforms

* delete invalid file

* add some empty doc file for rd

* delete some text alias

* add_tutorial test=develop

* fix quick start test=develop

As the title

* add migration test=develop

* fix_logs test=develop

* fix_migration_guide and add dygraph to static test=develop

* fix_install test=develop

* fix install and args

* fix_style test=develop

* fix docs test=develop

* update conv kl-loss doc

We added basic English usage guide. In addition, I thought some Chinese sentences are not good so I modified them.

TODO: Yamei suggested to split this file into basic usage and architecture. I will do it in next PRs

* add paddle.vision.transforms.* api cn doc

* add alias for paddle.vision.transforms

* delete invalid file

updata norm doc

* add model save load guide

* polish details

* fix index number

* polish hapi & add note

* add_totorial_for_paddle test=develop

* fix_index test=develop

* fix_index_tutorial test=develop

* fix_index test=develop

* fix_index test=develop

* fix_index test=develop

* fix index test=develop

* change_md_to_rst test=develop

* fix image path test=develop

* fix index test=develop

* fix image test=develop

* fix_image test=develop

* fix image test=develop

* change title test=develop

* add new ci_scripts for new paddle doc dirs

* fix path error

* fix path error

* update configs & 2.0 examples

* move apis directory

* update api names

* add new ci_scripts for new paddle doc dirs

* fix path error

* add_faq_index test=develop

* remove layout