Feature request - add support for KDJ or Stochastic Oscillator

[tsubus]

https://docs.anychart.com/Stock_Charts/Technical_Indicators/KDJ

https://www.investopedia.com/terms/s/stochasticoscillator.asp

Either one is fine, KDJ is based on stochasatic oscillator, it just adds the J line that represents the divergence between K and D. Useful for determining the right times to buy or sell.

[sdcoffey]

I'm into it! Feel free to submit a PR if you like, otherwise I'll try to get to it in the next few weeks

[tsubus]

I'm into it! Feel free to submit a PR if you like, otherwise I'll try to get to it in the next few weeks

#35