Fix Xcode case (Upper X, lower c)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@156742 91177308-0d34-0410-b5e6-96231b3b80d8

docs/Tooling.html

@@ -23,7 +23,7 @@ is probably the interface you want to use. Consider the other interfaces only
 when you have a good reason not to use LibClang.</p>
 <p>Canonical examples of when to use LibClang:</p>
 <ul>
-  <li>XCode</li>
+  <li>Xcode</li>
   <li>Clang Python Bindings</li>
 </ul>
 <p>Use LibClang when you...</p>