Fix imputing docu

[nils-braun]

Fixes #754

[github-actions]

You have style errors. See them below.

./tsfresh/transformers/feature_augmenter.py:115:121: E501 line too long (125 > 120 characters)
./tsfresh/feature_extraction/extraction.py:110:121: E501 line too long (121 > 120 characters)

[codecov-io]

Codecov Report

Merging #800 (3d1139c) into main (ece2327) will increase coverage by 0.02%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #800      +/-   ##
==========================================
+ Coverage   95.89%   95.91%   +0.02%     
==========================================
  Files          18       18              
  Lines        1777     1837      +60     
  Branches      347      362      +15     
==========================================
+ Hits         1704     1762      +58     
- Misses         36       37       +1     
- Partials       37       38       +1     

Impacted Files	Coverage Δ
tsfresh/feature_extraction/extraction.py	94.93% <ø> (ø)
tsfresh/transformers/feature_augmenter.py	100.00% <ø> (ø)
tsfresh/feature_extraction/feature_calculators.py	97.27% <0.00%> (-0.06%)	⬇️
tsfresh/feature_extraction/settings.py	100.00% <0.00%> (ø)
tsfresh/feature_selection/relevance.py	95.28% <0.00%> (ø)

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[github-actions]

You have style errors. See them below.

./tsfresh/transformers/feature_augmenter.py:115:104: W291 trailing whitespace
./tsfresh/feature_extraction/extraction.py:110:91: W291 trailing whitespace