Refit Miscelaneous

[wdykas]

What does this PR do ?

I told Claude to optimize the memory a bit and also write a readme so this is that. Also there is some general clean up from all the changes that have been getting forced in. There will be additional testing as well.

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[wdykas]

/ok to test 192ec38

[wdykas]

/ok to test 700db17

[wdykas]

@sidsingh-nvidia @santhnm2 @kvareddy not needed for the push were are on right now but whenever people have time and can take a look. This is a cleanup by Claude I reviewed that looks good and adds some documentation

[wdykas]

/ok to test 4589d22

[wdykas]

/ok to test 52e6f3e

[wdykas]

/ok to test edb88d7

[svcnvidia-nemo-ci]

🔄 Merge queue validation started!

You can track the progress here: https://github.com/NVIDIA/Megatron-LM/actions/runs/24259603870