[DOC]: update documents of colossal chat

[cwher]

Motivation

• Several issues regarding datasets and OOM have been proposed.
• The code has been refactored, and we should make the documentation align with the code.

Expected Results

• Run all examples in README. Make sure all the code snippets are runnable or we should mark them as outdated.
• Fixed factual errors or missing parts in README, e.g., where to find the dataset?
• Add notation for the results that are not easily reproducible, e.g., run examples that require 23.5GB device memory in a single RTX3090Ti.

Details

The following files are revised,

./examples/community/peft/README.md
./examples/community/ray/README.md
./examples/community/README.md
./examples/README.md
./benchmarks/README.md
./coati/ray/README.md
./README.md

except

./evaluate/README.md
./inference/README.md

Possible Future Work

• Revise benchmark results since the code has been refactored.
• Revise some algorithmic concepts. (This part is likely to be beyond my knowledge as a system engineer.)
• Add hyper-parameter tuning tutorial. (This part is also beyond my knowledge.)