Add bitcoin as a topic to this repository

Hello,

This repository is listed on the [Awesome Bitcoin](https://raw.githubusercontent.com/igorbarinov/awesome-bitcoin/master/README.md) list, which is a collection of useful Bitcoin projects. However, it seems that the 'bitcoin' topic is missing from this repository's topics.

Adding the 'bitcoin' topic will help users discover your project more easily and recognize its relevance to the Bitcoin ecosystem. To add the topic, please follow these steps:

1. Navigate to the main page of the repository.
2. Click on the gear icon next to "About" on the right side of the page.
3. In the "Topics" section, type 'bitcoin' and press Enter.
4. Click "Save changes."

Thank you for your attention and for contributing to the Bitcoin community!