* add outputs for code examples, test=document_fix

* missing code example update, test=document_fix

* missing returns, test=document_fix

* fix the case of proper nouns, test=document_fix

* fix SqueezeNet code example (add a blank line), test=document_fix

* fix ShuffleNetV2 args style, test=document_fix

* missing paper links, test=document_fix

* missing `optional`, test=document_fix

* refine parameter `pretrained`, test=document_fix

* add parameter `kwargs`, test=document_fix

* refine parameter `num_classes`, test=document_fix

* capitalize the first letter, test=document_fix

* missing output of code example, test=document_fix

* fix wrong api label, test=document_fix

* refine returns, test=document_fix

* add missing `.` after paper link, test=document_fix

* remove extra `:`, test=document_fix

* :math:\`0.0\`, test=document_fix

* use yapf to format all python file

* yapf exclude two unittests file for they rely on writing and reading file, and format will break them

* disable diff_py_file because too many diff files cause command following failed

* add mobilenetv3