Show progress bar history and changes for docs

[jeremyliweishih]

Solves #48.

[codecov]

Codecov Report

Merging #111 into master will increase coverage by 0.21%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #111      +/-   ##
==========================================
+ Coverage   93.72%   93.94%   +0.21%     
==========================================
  Files          52       54       +2     
  Lines        1355     1403      +48     
==========================================
+ Hits         1270     1318      +48     
  Misses         85       85

Impacted Files	Coverage Δ
evalml/demos/__init__.py	100% <100%> (ø)	⬆️
evalml/tests/model_type_tests/test_model_types.py	100% <100%> (ø)
evalml/pipelines/utils.py	100% <100%> (ø)	⬆️
evalml/models/auto_base.py	92.3% <100%> (+0.34%)	⬆️
evalml/objectives/__init__.py	100% <100%> (ø)	⬆️
evalml/pipelines/classification/__init__.py	100% <100%> (ø)	⬆️
evalml/__init__.py	100% <100%> (ø)	⬆️
evalml/model_types/utils.py	100% <100%> (ø)
evalml/model_types/__init__.py	100% <100%> (ø)	⬆️
evalml/pipelines/__init__.py	100% <100%> (ø)	⬆️
... and 2 more

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[kmax12]

this looks good, but we should also rerun the notebooks in the docs to reflect this change

[kmax12]

one comment, otherwise, looks good

[kmax12]

LGTM