feat: Introduce Demo Scripts Demonstrating Usage of load_file and preprocess

[happymealinthebuilding]

Added Demo Codes (For load_file and preprocess Functions)

This Pull Request (PR) includes demo codes demonstrating how to use the load_file and preprocess functions.

Changes:

• Added a demo script for the load_file function. This script shows how to read a specified .h5ad file, create an AnnData object, and print its basic information.
• Added a demo script for the preprocess function. This script demonstrates running the function on a sample AnnData object (either by creating a new one or loading an existing .h5ad file) and printing the basic information of the processed AnnData object.

How Tested:

• The demo codes were executed in a Jupyter Notebook environment.
• Verified that the load_file function successfully loaded the specified .h5ad file.
• Confirmed that the preprocess function successfully applied normalization, log transformation, regression, and scaling steps on the sample data.

Demo Output:

The screenshot is the output obtained from running the demo codes. The demonstration shows that the codes are working correctly.

Important Note:

This PR only includes demo codes, and no changes have been made to the main codebase.

Conclusion:

I believe that the added demo codes clearly illustrate the usage of the load_file and preprocess functions.