Fix Ingress resources in docs (#7579)

* fix Ingress resources in docs

Signed-off-by: Gerald Pape <gerald@giantswarm.io>

* move to ingressClassName

* fix more Ingress resource examples

* empty commit

Signed-off-by: Gerald Pape <gerald@giantswarm.io>

* make NOTES.txt aware of version + add notice about ingress version to examples main page

* add link to legacy documentation

Signed-off-by: Gerald Pape <gerald@giantswarm.io>

docs/examples/auth/external-auth/ingress.yaml

@@ -5,6 +5,7 @@ metadata:
     nginx.ingress.kubernetes.io/auth-url: "https://httpbin.org/basic-auth/user/passwd"
   name: external-auth
 spec:
+  ingressClassName: nginx
   rules:
   - host: external-auth-01.sample.com
     http:
@@ -15,4 +16,4 @@ spec:
           service:
             name: http-svc
             port:
-              number: 80
+              number: 80