Add linux.system.directory state

Change-Id: Ida91f545cc705457d1bc567fbee483e14a202a3a
diff --git a/README.rst b/README.rst
index a4d5323..1cbc18c 100644
--- a/README.rst
+++ b/README.rst
@@ -328,6 +328,19 @@
               DefaultLimitCPU: 2
               DefaultLimitNPROC: 4
 
+Ensure presence of directory:
+
+.. code-block:: yaml
+
+    linux:
+      system:
+        directory:
+          /tmp/test:
+            user: root
+            group: root
+            mode: 700
+            makedirs: true
+
 Kernel
 ~~~~~~