ExerciseList component is hardcoded to grab from index 0

[RileyCullen]

https://github.com/MasonAdsero/LiftoGraph/pull/11/files#diff-77c7674b4aa6a1b73428e1d7a8e2c311db8152a2a6f60443b551e192c148a98aR214

See above. The workout we grab should be dynamic, based on what's selected from the main UI