Update AvoidUninitializedVariable.md

Author: yutingc

RuleDocumentation/AvoidUninitializedVariable.md

@@ -17,8 +17,8 @@ Wrong：
 
 	function NotGlobal {
 	    $localVars = "Localization?"
-	    $unitialized
-	    Write-Output $unitialized
+	    $uninitialized
+	    Write-Output $uninitialized
 	}
 
 
@@ -27,4 +27,4 @@ Correct:
 	function NotGlobal {
 	    $localVars = "Localization?"
 	    Write-Output $localVars
-	}
+	}