Update index.md

Author: DamienIrving

index.md

@@ -7,11 +7,12 @@ keywords:
 title: Python for Atmosphere and Ocean Science
 description: Information and resources for the PyAOS community.
 buttons:
-    - content: Join the PyAOS discussion @ Scientific Python Discourse
+    - icon: discourse
+      content: Join the PyAOS discussion @ Scientific Python Discourse
       url: 'https://discuss.scientific-python.org/c/contributor/pyaos/28'
       external_url: true
     - icon: github
-      content: Contribute on GitHub
+      content: Contribute to this website on GitHub
       url: 'https://github.com/PyAOS/pyaos.github.io'
       external_url: true