kubectl create secret generic --help does not describe type

**What would you like to be added**:
the command "kubectl create secret generic --help"

does not describe the type option.

```
$ kubectl create secret generic --help
Create a secret based on a file, directory, or specified literal value.

A single secret may package one or more key/value pairs.

...

Examples:
# Create a new secret named my-secret with keys for each file in folder bar
kubectl create secret generic my-secret --from-file=path/to/bar

# Create a new secret named my-secret with specified keys instead of names on disk
kubectl create secret generic my-secret --from-file=ssh-privatekey=path/to/id_rsa --from-file=ssh-publickey=path/to/id_rsa.pub

# Create a new secret named my-secret with key1=supersecret and key2=topsecret
kubectl create secret generic my-secret --from-literal=key1=supersecret --from-literal=key2=topsecret

# Create a new secret named my-secret using a combination of a file and a literal
kubectl create secret generic my-secret --from-file=ssh-privatekey=path/to/id_rsa --from-literal=passphrase=topsecret

# Create a new secret named my-secret from env files
kubectl create secret generic my-secret --from-env-file=path/to/foo.env --from-env-file=path/to/bar.env

Options:
...
--type='':
The type of secret to create
...
```

**Why is this needed**:

No example. No description of what type is allowed.

working example:

```
$ kubectl create secret generic quay-registry \
--from-file .dockerconfigjson=${XDG_RUNTIME_DIR}/containers/auth.json \
--type kubernetes.io/dockerconfigjson
```