add plugin add/remove commands

Signed-off-by: Steve Kriss <steve@heptio.com>

docs/cli-reference/ark_plugin_remove.md

@@ -0,0 +1,35 @@
+## ark plugin remove
+
+Remove a plugin
+
+### Synopsis
+
+
+Remove a plugin
+
+```
+ark plugin remove [NAME | IMAGE] [flags]
+```
+
+### Options
+
+```
+  -h, --help   help for remove
+```
+
+### Options inherited from parent commands
+
+```
+      --alsologtostderr                  log to standard error as well as files
+      --kubeconfig string                Path to the kubeconfig file to use to talk to the Kubernetes apiserver. If unset, try the environment variable KUBECONFIG, as well as in-cluster configuration
+      --log_backtrace_at traceLocation   when logging hits line file:N, emit a stack trace (default :0)
+      --log_dir string                   If non-empty, write log files in this directory
+      --logtostderr                      log to standard error instead of files
+      --stderrthreshold severity         logs at or above this threshold go to stderr (default 2)
+  -v, --v Level                          log level for V logs
+      --vmodule moduleSpec               comma-separated list of pattern=N settings for file-filtered logging
+```
+
+### SEE ALSO
+* [ark plugin](ark_plugin.md)	 - Work with plugins
+