Regen docs

Signed-off-by: Andy Goldstein <andy.goldstein@gmail.com>

docs/cli-reference/ark_plugin.md

@@ -21,6 +21,7 @@ Work with plugins
       --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
+  -n, --namespace string                 The namespace in which Ark should operate (default "heptio-ark")
       --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