Add Keygen to Misc (#3975)

non-free.md

@@ -180,6 +180,7 @@
 
 ### Miscellaneous
 
+ - [Keygen](https://github.com/keygen-sh/keygen-api) - Self-hosted software licensing and distribution API. `Elastic-2.0` `Ruby`
  - [RemoteUtilities](https://www.remoteutilities.com/) - Remote Utilities is self-hosted remote support software for LAN administration and remote support over the Internet. `⊘ Proprietary` `Unknown`
  - [ScreenConnect](https://www.connectwise.com/platform/unified-management/control) - Lightning-fast remote support and remote access to connect instantly and solve problems faster. `⊘ Proprietary` `Unknown`
 
@@ -198,5 +199,6 @@
 - `CC-BY-NC-4.0` - [Creative Commons Attribution-NonCommercial License 4.0](https://creativecommons.org/licenses/by-nc/4.0/)
 - `Commons-Clause` - [Commons Clause License](https://commonsclause.com/)
 - `DPL` - [Devblocks Public License 1.0](https://cerb.ai/license/)
+- `Elastic-2.0` - [Elastic License 2.0](https://spdx.org/licenses/Elastic-2.0.html)
 - `SSPL-1.0` - [Server Side Public License](https://spdx.org/licenses/SSPL-1.0.html)
 - `⊘ Proprietary` - [Proprietary software](https://en.wikipedia.org/wiki/Proprietary_software)