Added ssh-keys default help function

plugins/ssh-keys/functions

@@ -2,6 +2,25 @@
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 source "$PLUGIN_CORE_AVAILABLE_PATH/common/functions"
 
+help_formatted (){
+	echo -e 'Usage: dokku ssh-keys[:COMMAND]'
+	echo ''
+	echo 'Manage public ssh keys that are allowed to connect to Dokku'
+	echo ''
+	echo 'Additional commands:'
+	help_content_func | sort | column -c2 -t -s,
+}
+
+help_content_func () {
+      declare desc="return ssh-keys plugin help content"
+      cat<<help_content
+    ssh-keys, Manage public ssh keys that are allowed to connect to Dokku
+    ssh-keys:list, List of all authorized dokku public ssh keys
+    ssh-keys:add <name> [/path/to/key], Add a new public key by pipe or path
+    ssh-keys:remove <name>, Remove SSH public key by name
+help_content
+    }
+
 verify_ssh_key_file() {
   declare desc="Test that public key is valid"
   [[ -s ${DOKKU_ROOT}/.ssh/authorized_keys ]] || dokku_log_fail "No public keys found."