
### Key Sections:
1. **Features**: Overview of what the library can do.
2. **Installation**: Instructions on how to install the library via `pip`.
3. **Usage**: Example code snippets showing how to use the functions in the library (`calculate_returns` and `checkout`).
4. **Functions**: Explanation of the functions available, including parameters and return types.
5. **Contributing**: Encouragement for others to contribute to the project.
6. **License**: Information about the license under which the library is released (MIT License in this case).

You can edit the README as needed depending on the exact functionalities of your library.
