docs: [CMake] Add Xcode to the list of project formats CMake can generate.

Suggested by Sean McBride, thanks!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@168745 91177308-0d34-0410-b5e6-96231b3b80d8

www/get_started.html

@@ -85,7 +85,7 @@ follows:</p>
     <li>Note: For subsequent Clang development, you can just do make at the
     clang directory level.</li>
     <li>It is also possible to use CMake instead of the makefiles. With CMake
-    it is also possible to generate project files for several IDEs: Eclipse
+    it is possible to generate project files for several IDEs: Xcode, Eclipse
     CDT4, CodeBlocks, Qt-Creator (use the CodeBlocks generator), KDevelop3.</li>
   </ul>
   </li>