Rename threshold_keys

[teubert]

Rename threshold_keys to events to align with terminology in predictor. threshold_keys will still work, but will warn. added test and updated examples

[github-actions]

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[codecov-commenter]

Codecov Report

Attention: Patch coverage is 91.52542% with 5 lines in your changes missing coverage. Please review.

Project coverage is 83.36%. Comparing base (0980f8c) to head (1ace59a).
Report is 37 commits behind head on dev.

Files	Patch %	Lines
src/progpy/prognostics_model.py	81.81%	4 Missing ⚠️
src/progpy/data_models/lstm_model.py	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##              dev     #147      +/-   ##
==========================================
- Coverage   83.41%   83.36%   -0.06%     
==========================================
  Files         100      100              
  Lines       10462    10553      +91     
==========================================
+ Hits         8727     8797      +70     
- Misses       1735     1756      +21     

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[kjjarvis]

This is a nice change for clear language use. All tests and notebooks run successfully

[kjjarvis]

Should this be deleted?

[teubert]

Argh- Git doesn't handle jupyter notebooks very well.

This isn't a problem, so I'm going to ignore it.