docs: add A2A Net to partners list (a2aproject#1201)

Added A2A Net to the list of partners.

Author: benclarkeio

docs/partners.md

@@ -5,6 +5,7 @@ if available) who are part of the A2A community and are helping build, codify,
 and adopt A2A as the standard protocol for AI agents to communicate and
 collaborate effectively with each other and with users.
 
+- [A2A Net](https://a2anet.com)
 - [Accelirate Inc](https://www.accelirate.com)
 - [Accenture](https://www.accenture.com)
 - [Activeloop](https://www.activeloop.ai/)