Efficient way of applying ColumnTransformer

[varunvilva]

In the initial dummy notebook suggest ways for applying ColumnTransformer before the pipelining step in a efficient manner. Discuss here what you think must be done. Pull requests are appreciated.

[AnujSaha0111]

we can use it to handle preprocessing for both numerical and categorical columns in a single step.
By applying transformations like scaling, encoding, and imputation within ColumnTransformer, we can streamline the process and ensure consistent data handling across the dataset.