[doc] Add the bug fix information for ipython user

[nabenabe0928]

After the installation by following README, we will get an unwanted error regarding ipython.
Basically, we will not be able to use ipython by NoModuleFoundError at all, because we change the base conda setting.

The command that yields the error is conda install gxx_linux-64 gcc_linux-64 swig and this can be fixed by unset _CONDA_PYTHON_SYSCONFIGDATA_NAME.
The unset command unsets the environment variable.

You can reproduce this issue by the followings:

$ conda install gxx_linux-64 gcc_linux-64 swig
$ conda activate <Any environments>
$ which ipython
# Check the ipython refers to one of the conda environments
$ ipython
# This yields an error
 
$ unset _CONDA_PYTHON_SYSCONFIGDATA_NAME
# This environment variable is originally None, so we need to reset it
# ==> it fixes the issue.

[codecov]

Codecov Report

Merging #254 (0ce2970) into development (1818445) will not change coverage.
The diff coverage is n/a.

@@             Coverage Diff              @@
##           development     #254   +/-   ##
============================================
  Coverage        80.82%   80.82%           
============================================
  Files              148      148           
  Lines             8563     8563           
  Branches          1323     1323           
============================================
  Hits              6921     6921           
  Misses            1163     1163           
  Partials           479      479           

Impacted Files	Coverage Δ
...components/setup/network_initializer/XavierInit.py	81.81% <0.00%> (-18.19%)	⬇️
...nts/setup/network_backbone/ConvNetImageBackbone.py	96.07% <0.00%> (-3.93%)	⬇️
autoPyTorch/ensemble/ensemble_builder.py	72.70% <0.00%> (+0.83%)	⬆️

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