[README] added conference registration link (#8114)

Author: ptillet

README.md

@@ -6,6 +6,11 @@
 |-------------------- | -------------------- |
 | [![Documentation](https://github.com/triton-lang/triton/actions/workflows/documentation.yml/badge.svg)](https://triton-lang.org/) | [![Wheels](https://github.com/triton-lang/triton/actions/workflows/wheels.yml/badge.svg)](https://github.com/triton-lang/triton/actions/workflows/wheels.yml) |
 
+# Conference Registration
+
+The 3rd Triton conference is scheduled to take place on October 21, 2025. Click [here](https://tritonconference.eventbuilder.com/TritonDeveloperConference) to register!
+
+
 # Triton
 
 This is the development repository of Triton, a language and compiler for writing highly efficient custom Deep-Learning primitives. The aim of Triton is to provide an open-source environment to write fast code at higher productivity than CUDA, but also with higher flexibility than other existing DSLs.