docs(helm-search): update helm_search docs

Signed-off-by: Art Begolli <artbegolli@gmail.com>

docs/helm/helm_search.md

@@ -20,6 +20,7 @@ helm search [keyword] [flags]
 ```
       --col-width uint   Specifies the max column width of output (default 60)
   -h, --help             help for search
+  -o, --output string    Show the output in specified format
   -r, --regexp           Use regular expressions for searching
   -v, --version string   Search using semantic versioning constraints
   -l, --versions         Show the long listing, with each version of each chart on its own line
@@ -41,4 +42,4 @@ helm search [keyword] [flags]
 
 * [helm](helm.md)	 - The Helm package manager for Kubernetes.
 
-###### Auto generated by spf13/cobra on 16-May-2019
+###### Auto generated by spf13/cobra on 12-Aug-2019