Merge pull request #171 from chaitanya1731/doc

device_plugins: Updated the latest operator version to v0.28.0

Author: uMartinXu

device_plugins/install_operator.yaml

@@ -20,4 +20,4 @@ spec:
   name: intel-device-plugins-operator
   source: certified-operators
   sourceNamespace: openshift-marketplace
-  startingCSV: intel-device-plugins-operator.v0.26.2
+  startingCSV: intel-device-plugins-operator.v0.28.0