docs(rulesets): add v3 to AsyncAPI support docs (#2755)

Co-authored-by: Nauman <mnaumanali94@gmail.com>

Author: frankkilcommins

docs/getting-started/5-asyncapi.md

@@ -2,6 +2,6 @@
 
 Spectral has a built-in AsyncAPI [v2](https://v2.asyncapi.com/docs/reference/specification/v2.6.0) and [v3](https://www.asyncapi.com/docs/reference/specification/v3.0.0) ruleset that you can use to validate your AsyncAPI files.
 
-Add `extends: "spectral:asyncapi"` to your ruleset file to apply rules for AsyncAPI v2.
+Add `extends: "spectral:asyncapi"` to your ruleset file to apply rules for AsyncAPI v2 and v3.
 
 You can see a full list of the rules in this ruleset in [AsyncAPI Rules](../reference/asyncapi-rules.md).