* init shardformer code structure
* add implement of sharder (inject and replace)
* add implement of replace layer to colossal layer
* separate different layer policy, add some notion
* implement 1d and 2d slicer, can tell col or row
* fix bug when slicing and inject model
* fix some bug; add inference test example
* init shardformer code structure
* add implement of sharder (inject and replace)
* add implement of replace layer to colossal layer
* separate different layer policy, add some notion
* implement 1d and 2d slicer, can tell col or row
* fix bug when slicing and inject model
* fix some bug; add inference test example