Update module docstrings for clarity and context

Expanded the docstrings in simulate.py and statistics.py to provide more detailed descriptions of their purposes and functionalities, improving documentation for users and developers working with connectivity analysis.

Author: edeno

spectral_connectivity/simulate.py

@@ -1,4 +1,9 @@
-"""Functions to simulate processes."""
+"""Functions to simulate time series processes for connectivity analysis.
+
+This module provides functions for generating synthetic time series data
+following various dynamical models, primarily multivariate autoregressive
+(MVAR) processes commonly used for testing connectivity methods.
+"""
 
 from typing import Optional, Union
 

spectral_connectivity/statistics.py

@@ -1,4 +1,11 @@
-"""Common statistical procedures used with frequency domain measures."""
+"""Statistical procedures for connectivity analysis.
+
+This module provides statistical functions for testing significance of
+connectivity measures, including multiple comparison corrections and
+transforms for coherence-based measures. Functions support both parametric
+and non-parametric approaches for statistical inference in frequency domain
+connectivity analysis.
+"""
 
 from typing import Callable, Dict, Literal, Tuple, Union