feat(model): Add learning rate scheduler

[boss-chanon]

Why this PR

Add learning rate scheduler by base from https://github.com/Lightning-AI/lit-llama/blob/c3c43b6a911f3d6be5b5b3a16e844202647060e5/pretrain/redpajama.py#L299

Changes

• Add learning rate scheduler to train pipeline
• Add learning rate scheduler config
• Add learning rate scheduler README

Related Issues

Close #

Checklist

• [ ] PR should be in the Naming convention
• [ ] Assign yourself in to Assigneees
• [ ] Tag related issues
• [ ] Constants name should be ALL_CAPITAL, function name should be snake_case, and class name should be CamelCase
• [ ] complex function/algorithm should have Docstring
• [ ] 1 PR should not have more than 200 lines changes (Exception for test files). If more than that please open multiple PRs
• [ ] At least PR reviewer must come from the task's team (model, eval, data)