Update README.md (#524)

Corrected the heading

Author: talonx

examples/simple_zonal_private/README.md

@@ -1,6 +1,6 @@
-# Simple Regional Cluster
+# Simple Zonal Cluster
 
-This example illustrates how to create a simple private cluster.
+This example illustrates how to create a simple private cluster in a single zone.
 
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 ## Inputs