* add ipu related authors, test=document_fix

* add gc, test=document_fix

Co-authored-by: NLi Min <11663212+limin2021@users.noreply.github.com>
Co-authored-by: Zhou Wei <1183042833@qq.com>
Co-authored-by: littletomatodonkey <dazhiningsibuqu@163.com>
Co-authored-by: Nzhupengyang <1165938320@qq.com>
Co-authored-by: NSiming Dai <908660116@qq.com>
Co-authored-by: Njiangcheng <thisjiang@qq.com>
Co-authored-by: NGuanghua Yu <742925032@qq.com>
Co-authored-by: NTeFeng Chen <ctfeng66@163.com>
Co-authored-by: NZhong Hui <zhonghui.net@gmail.com>
Co-authored-by: Nliu zhengxi <380185688@qq.com>
Co-authored-by: NJason <928090362@qq.com>
Co-authored-by: NDingjiawei <327396238@qq.com>
Co-authored-by: NChen Weihang <chenweihang@baidu.com>

Signed-off-by: NZhang Jun <jzhang533@gmail.com>
Signed-off-by: NZhang Jun <jzhang533@gmail.com>

* remove stats_md

* add entry to authors.md

* supports distributed classification training
* update API.spec
* fix evenly division in python3
* change "index_range" to "index_num" in shard_index operator
test=document_preview
test=develop

* remove async executor and add data_feed.proto to the deps of train demo

add sfraczek
add wojtuss

test=develop

Add group normalization operator.

test=develop

test=develop