Add Sadeh algorithms for sleep-wake scoring

[danielvartan]

Comments in English, Spanish, or Portuguese are welcome.
Comentarios en inglés, español o portugués son bienvenidos.
Comentários em inglês, espanhol ou português são bem-vindos.

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Instructions

• Create a branch called feature/sadeh.
• See all the references in the basic references section before starting the development.
• The function must take an object of class tsibble (mandatory).
• Add a vignette, with practical examples, explaining the features.
• All exported functions must be fully documented.
• All functions must be accompanied by unit tests (100% coverage).
• References in the documentation must be formatted in accordance with the APA (American Psychological Association) manual.
• When finished, create a PR to the main branch. Don't forget to mention this issue when creating your PR.

Materials

• Actigraphy log.
• Guidelines for Contributing.

Basic references

• Sadeh, A., Alster, J., Urbach, D., & Lavie P. (1989). Actigraphically based automatic bedtime sleep-wake scoring: validity and clinical application. Journal of Ambulatory Monitoring, 2(3), 209-216. https://bit.ly/3IMkoir
• Sadeh, A., Sharkey, M., & Carskadon, M. A. (1994). Activity-based sleep-wake identification: an empirical test of methodological issues. Sleep, 17(3), 201-207. https://doi.org/10.1093/sleep/17.3.201
• Sadeh, A., Acebo, C., Seifer, R., Aytur, S., & Carskadon, M. A. (1995). Activity-based assessment of sleep-wake patterns during the 1st year of life. Infant Behavior and Development, 18(3), 329-337. https://doi.org/10.1016/0163-6383(95)90021-7
• Sadeh, A. (2011). The role and validity of actigraphy in sleep medicine: an update. Sleep Medicine Reviews, 15(4), 259-267. https://doi.org/10.1016/j.smrv.2010.10.001

Other references

• American Psychological Association. (2020). Publication manual of the American Psychological Association (7th ed.).
  https://doi.org/10.1037/0000165-000