GitLab

* s3dis sem seg data doc

* minor fix

* fix typo

* fix blank space

* remove untricky code block

* support S3DIS data download and pre-processing (to ScanNet format)

* add S3DIS data for unittest

* add S3DIS semseg dataset class and unittest

* add config file for S3DIS dataset

* add eval_pipeline to S3DIS dataset config file

* clean code for S3DIS pre-processing scripts

* reformat code

* fix small bugs

* resolve conflicts & modify show() to use pipeline

* fix small errors

* polish data pre-processing code

* add more comments about S3DIS dataset

* fix markdown lint error