Add PublicZone.org to subdomain list

Added PublicZone.org as a new free subdomain option with details on supported SLDs and conditions.

Author: wdhdev

data/Domains.md

@@ -10,5 +10,6 @@
 | [Open Domains](https://open-domains.net) | Free subdomains for personal sites, open-source projects, and more. | ✅ |
 | [Open Host](https://registry.openhost.uk) | A free subdomain service offering subdomains on `prvcy.page`, `16-b.it`, `32-b.it`, `64-b.it`, `pride.moe` and `pride.ngo`. | ⚠️ `pride.moe` and `pride.ngo` are not listed. |
 | [pp.ua](https://pp.ua) | Free pp.ua subdomains. | ✅ |
+| [PublicZone.org](https://publiczone.org) | Free subdomains across multiple SLDs (`.nyc.mn`, `.int.al`, `.cn.st` variants) funded through charitable donations or GitHub developers program (free domains for GitHub projects with 100+ stars) | ✅ `.nyc.mn`, `.cn.st` are listed. ⚠️ `.int.al` is not listed. |
 | [us.kg](https://nic.us.kg) | Free subdomain service run by the nonprofit DigitalPlat Foundation, supported by the Hack Foundation. | ✅ |
 | [Zone.ID](https://zone.id/) | Zone.ID is a premium subdomain provider as an alternative to the traditional .id TLD. | ✅ |