Add detailed docstrings to all functions in src/model/models.py

[Aaryan-549]

Problem

Many functions in src/model/models.py lack proper docstrings or have minimal documentation. This makes it hard for new contributors to understand function parameters, return values, and usage.

Proposed Solution

Add comprehensive Google-style docstrings to all functions including:

• Function description
• Args with types
• Returns with types
• Raises (if applicable)
• Examples

Functions to Document

• normalize_features()
• plot_feature_importance()
• plot_loss_curve()
• train_linear_regression()
• train_ridge_regression()
• And all other training functions

Example

def normalize_features(X):
    """
    Normalize features into different ranges for model training.
    
    Args:
        X (pd.DataFrame): Input features containing coordinates, distances, 
                         precipitation, time features, and flags
    
    Returns:
        pd.DataFrame: Normalized features with:
            - Coordinates scaled to (-1, 1)
            - Distances scaled to (0, 10)
            - Precipitation scaled to (0, 1)
            - Time features scaled to (0, 5)
    
    Examples:
        >>> X_normalized = normalize_features(train_df.drop('duration', axis=1))
    """

[harshitaphadtare]

@Aaryan-549 assigned!

[Aaryan-549]

@harshitaphadtare I have created a pull request (#37) completing the task. Please have a look.