[docs] Update deepspeed docs, add some more information and link to streamlit

[SeanNaren]

What does this PR do?

Updates the DeepSpeed docs with reference to single file checkpointing when using ZeRO 3 + some helpful information.

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[codecov]

Codecov Report

Merging #8691 (a33961a) into master (a1be621) will decrease coverage by 4%.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master   #8691    +/-   ##
=======================================
- Coverage      93%     89%    -4%     
=======================================
  Files         167     167            
  Lines       14037   14037            
=======================================
- Hits        13008   12453   -555     
- Misses       1029    1584   +555     

[tchaton]

LGTM !