Add documentation for all analysis technique

[yacineMahdid]

This will help when writing abstract/paper since the formula and the inner working of the algorithm will already be written in detail.

[yacineMahdid]

Here actually we should have two type of documentation, one for the math behind the analysis technique with references to the relevant papers and another only for the how to use the code.

[yacineMahdid]

Power Spectra

• [ ] Math
• [ ] Code

  Topographic Distribution of Power

• [ ] Math
• [ ] Code

  Permutation Entropy

• [ ] Math
• [ ] Code

  Weighted Phase Lag Index

• [x] Math
• [ ] Code

  Directed Phase Lag Index

• [x] Math
• [ ] Code