Fix docs that are rendering Incorrectly (#7344)

Fixes #6747 

### Changes

- Added missing imports required for the documentation to render
correctly.
- Changed `autoclass_content` from `auto` to `both`
The value `auto` is **not valid** according to the [Sphinx
documentation](https://www.sphinx-doc.org/en/master/usage/extensions/autodoc.html#confval-autoclass_content).


### Preview

Sample fixed page:
https://deepspeedfelixgondwefork.readthedocs.io/en/latest/model-checkpointing.html

Current broken page:
https://deepspeed.readthedocs.io/en/latest/model-checkpointing.html

---------

Signed-off-by: felixgondwe <zungwala@gmail.com>
Signed-off-by: Shaik Raza Sikander <srsikander@habana.ai>
Signed-off-by: Masahiro Tanaka <mtanaka@microsoft.com>
Signed-off-by: Olatunji Ruwase <olruwase@microsoft.com>
Signed-off-by: Olatunji Ruwase <tunji.ruwase@snowflake.com>
Signed-off-by: xiongjyu <xiongjyu@gmail.com>
Signed-off-by: Emmanuel Ferdman <emmanuelferdman@gmail.com>
Co-authored-by: Quentin Gallouédec <45557362+qgallouedec@users.noreply.github.com>
Co-authored-by: Olatunji Ruwase <tjruwase@gmail.com>
Co-authored-by: Raza Sikander <srsikander@habana.ai>
Co-authored-by: Masahiro Tanaka <81312776+tohtana@users.noreply.github.com>
Co-authored-by: Logan Adams <114770087+loadams@users.noreply.github.com>
Co-authored-by: Ramya Ramineni <62723901+rraminen@users.noreply.github.com>
Co-authored-by: Olatunji Ruwase <tunji.ruwase@snowflake.com>
Co-authored-by: jerryyangli <jerryyangli@gmail.com>
Co-authored-by: Yang Li <yangli2@microsoft.com>
Co-authored-by: Guanhua Wang <alexwgh333@gmail.com>
Co-authored-by: Connor Holmes <connorholmes@microsoft.com>
Co-authored-by: Bing Xie <67908712+xiexbing@users.noreply.github.com>
Co-authored-by: cassieesvelt <73311224+cassieesvelt@users.noreply.github.com>
Co-authored-by: Jeff Rasley <jerasley@microsoft.com>
Co-authored-by: Michael Wyatt <michaelwyatt@microsoft.com>
Co-authored-by: Carlos Mocholí <carlossmocholi@gmail.com>
Co-authored-by: swli <47371259+lucasleesw@users.noreply.github.com>
Co-authored-by: Cheng Li <pistasable@gmail.com>
Co-authored-by: Molly Smith <112220543+molly-smith@users.noreply.github.com>
Co-authored-by: Ubuntu <jomayeri@microsoft.com>
Co-authored-by: Zhipeng Wang <zhipeng.rainbowserie@gmail.com>
Co-authored-by: xiongjyu <xiongjyu@gmail.com>
Co-authored-by: Emmanuel Ferdman <emmanuelferdman@gmail.com>

docs/code-docs/source/conf.py

@@ -96,6 +96,6 @@ sys.path.insert(0, os.path.abspath('../../../'))
 # Prepend module names to class descriptions?
 add_module_names = True
 
-autoclass_content = 'auto'
+autoclass_content = 'both'
 
-autodoc_mock_imports = ["apex", "mpi4py", "tensorboardX", "numpy", "cupy"]
+autodoc_mock_imports = ["apex", "mpi4py", "tensorboardX", "numpy", "cupy", "einops", "transformers", "msgpack"]