Incorporate Zelmann (i.e. MNI) Detector from Ripplelab

Zelmann detector is implemented in ripple lab. She also shared w/ us the source code and dataset for annotations.

@rachel to grab the raw source data from Krit/Beth/Jean?

References
- https://pubmed.ncbi.nlm.nih.gov/32932244/

Ripple lab
- https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0158276
- https://github.com/BSP-Uniandes/RIPPLELAB