GitLab

* WIP: api

* dgl.sampling, dgl.data

* dgl.sampling; dgl.dataloading

* sampling packages

* convert

* subgraph

* deprecate

* subgraph APIs

* All docstrings for convert/subgraph/transform

* almost all funcs under dgl namespace

* WIP: DGLGraph

* done graph query

* message passing functions

* lint

* fix merge error

* fix test

* lint

* fix
Co-authored-by: Quan Gan <coin2028@hotmail.com>

* add chebconv

* fix

* lint

* fix lint

* docs

* [Doc] User guide section 5 and 6

* oops

* fix

* upd

* upd

* upd

* upd

* upd

* upd

* upd

* upd

* several nn example

* appnp

* fix lint

* lint

* add dgi

* fix

* fix

* fix

* fff

* docs

* 111

* fix

* change init

* change result

* tiaocan+1

* fix

* fix lint

* fix

* fix