Add clarity around the phrase pull request

Signed-off-by: Lucas Roesler <[email protected]>

Author: LucasRoesler

docs/deployment/kubernetes.md

@@ -211,7 +211,7 @@ To enable SSL while using Helm, try one of the following references:
 If you are using a hosted private Docker registry ([Docker Hub](https://hub.docker.com/), or other),
 in order to check how to configure it, please visit the Kubernetes [documentation](https://kubernetes.io/docs/concepts/containers/images/#using-a-private-registry).
 
-If you try to deploy using `faas-cli deploy` it will fail because the Kubernetes kubelet component will not have credentials to authorize the pull request.
+If you try to deploy using `faas-cli deploy` it will fail because the Kubernetes kubelet component will not have credentials to authorize the docker image pull request.
 
 Once you have pushed an image to a private registry using `faas-cli push` follow the instructions below to either create a pull secret that can be referenced by each function which needs it, or create a secret for the ServiceAccount in the `openfaas-fn` namespace so that any functions which need it can make use of it.