text: Title: Bill Williams Fractals with Alligator Indicators
  Body: **Which version are you running? The lastest version is on Github. Pip is for major releases.**
  ```python
  import pandas_ta as ta
  print(ta.version)
  ```
  0.2.23b0
  
  **Upgrade.**
  ```sh
  $ pip install -U git+https://github.com/twopirllc/pandas-ta
  ```
  0.2.28b0
  
  **Is your feature request related to a problem? Please describe.**
  No
  
  **Describe the solution you'd like**
  Implementation of Bill Williams Alligator and Fractals indicators
  
  **Describe alternatives you've considered**
  See below links
  https://pandastechindicators.readthedocs.io/en/latest/#alligator
  https://pandastechindicators.readthedocs.io/en/latest/#fractals
  https://www.tradingview.com/script/lLgCdjag-Bill-Williams-Divergent-Bars/
  
  **Additional context**
  Some good code already available.
  https://github.com/Tolkoton/WilliamsIndicators/blob/master/WilliamsIndicators.py
  https://github.com/dmitriiweb/tapy
  
  Also if possible implement crossover like in this => https://tulipindicators.org/list
  