remove Digital Currency (unmaintained, dead links)

- unmaintained since 2021 https://github.com/Icesofty/Digital-Currency/commits/master
- demo page returns error 'Oops! This project isn't running.'
- ref. https://github.com/awesome-selfhosted/awesome-selfhosted/issues/2266

README.md

@@ -1293,7 +1293,6 @@ Software that does not fit in another section.
 - [CyberChef](https://github.com/gchq/CyberChef) - Perform all manner of operations within a web browser such as AES, DES and Blowfish encryption and decryption, creating hexdumps, calculating hashes, and much more. ([Demo](https://gchq.github.io/CyberChef)) `Apache-2.0` `Javascript`
 - [DailyTxT](https://github.com/PhiTux/DailyTxT) - Encrypted Diary Web-App to save your personal memories of each day. Includes a search-function and encrypted file-upload. `MIT` `Python`
 - [Databunker](https://databunker.org/) - Network-based, self-hosted, GDPR compliant, secure database for personal data or PII. ([Source Code](https://github.com/securitybunker/databunker)) `MIT` `Go`
-- [Digital-Currency](https://github.com/Icesofty/Digital-Currency) - Create your own Self-Hosted Digital Currency. ([Demo](https://tonken.glitch.me/)) `GPL-3.0` `Nodejs`
 - [DomainMOD](https://domainmod.org) - Application to manage your domains and other internet assets in a central location. DomainMOD includes a Data Warehouse framework that allows you to import your WHM/cPanel web server data so that you can view, export, and report on your data. ([Demo](https://demo.domainmod.org), [Source Code](https://github.com/domainmod/domainmod)) `GPL-3.0` `PHP`
 - [DOMJudge](https://www.domjudge.org/) - A system for running a programming contest, like the ICPC regional and world championship programming contests. ([Demo](https://www.domjudge.org/demo), [Source Code](https://github.com/DOMjudge/domjudge)) `GPL-2.0/BSD-3-Clause/MIT` `PHP`
 - [F-Droid](https://f-droid.org) - Server tools for maintaining an F-Droid repository system. ([Source Code](https://gitlab.com/fdroid/fdroidserver)) `AGPL-3.0` `Python/Docker`