Use CNCF-wording for maintainers

Use copyright notice wording required by CNCF for the maintainers field
for both Chart.yaml files.

Also fix an indentation error in one Chart.yaml file.

Signed-off-by: Daniel Farrell <dfarrell@redhat.com>

submariner-k8s-broker/Chart.yaml

@@ -6,7 +6,8 @@ description: Submariner Kubernetes Broker
 keywords:
 home: https://submariner-io.github.io/
 sources:
-- https://submariner-io.github.io/submariner-charts/charts
+  - https://submariner-io.github.io/submariner-charts/charts
 maintainers:
-- name: Submariner Developers
-  email: submariner-dev@googlegroups.com
+  - name: Contributors to the Submariner project
+    email: submariner-dev@googlegroups.com
+    url: https://submariner.io/

submariner-operator/Chart.yaml

@@ -8,5 +8,6 @@ home: https://submariner-io.github.io/
 sources:
   - https://submariner-io.github.io/submariner-charts/charts
 maintainers:
-  - name: Submariner Developers
+  - name: Contributors to the Submariner project
     email: submariner-dev@googlegroups.com
+    url: https://submariner.io/