Add DeepSpeed Stage 1 + doc improvements for model parallel

[SeanNaren]

What does this PR do?

Adds DeepSpeed Stage 1 as a configuration + improvements/additions to the doc. This is required for the Torch ORT integration.

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[codecov]

Codecov Report

Merging #8974 (47ba7b1) into master (38ceb89) will increase coverage by 0%.
The diff coverage is 100%.

@@          Coverage Diff           @@
##           master   #8974   +/-   ##
======================================
  Coverage      89%     89%           
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  Files         176     176           
  Lines       14411   14412    +1     
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+ Hits        12772   12773    +1     
  Misses       1639    1639