Fix typo in control_structures.md

Signed-off-by: Jon Huhn <Jon.Huhn@ibm.com>
Signed-off-by: Jon Huhn <hunjon@gmail.com>

docs/chart_template_guide/control_structures.md

@@ -269,7 +269,7 @@ It will produce an error because `Release.Name` is not inside of the restricted
   release: {{ .Release.Name }}
 ```
 
-After looking a `range`, we will take a look at template variables, which offer one solution to the scoping issue above.
+After looking at `range`, we will take a look at template variables, which offer one solution to the scoping issue above.
 
 ## Looping with the `range` action