Fix indentation

Author: donnie-msft

docs/reference/nuget-config-file.md

@@ -499,12 +499,12 @@ Below is an example `nuget.config` file that illustrates a number of settings in
     <!-- Used to enforce that certain packages only come from specific package sources. -->
     <packageSourceMapping>
       <clear />
-        <packageSource key="MyRepo - ES">
-            <package pattern="ES.*" />
-        </packageSource>
-        <packageSource key="NuGet official package source">
-            <package pattern="*" />
-        </packageSource>
+      <packageSource key="MyRepo - ES">
+        <package pattern="ES.*" />
+      </packageSource>
+      <packageSource key="NuGet official package source">
+        <package pattern="*" />
+      </packageSource>
     </packageSourceMapping>
 
     <!-- Used to store credentials -->