[DOC]: Update the documentation of ShardConfig for 1D, 2D, 2.5D, 3D tensor parallelism

[giriprasad51]

📚 The doc issue

Hi @FrankLeeeee , @ver217 please update the https://github.com/hpcaitech/ColossalAI/blob/main/colossalai/shardformer/README.md file

# tensor_parallel_mode: Literal['1d', '2d', '2.5d', '3d'] this line is commented in ShardConfig but documentation is not updated Its hard to use 2D,2.5D, 3D tensor parallelism