[docs] Add link to presentation slides.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184518 91177308-0d34-0410-b5e6-96231b3b80d8
Add test.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@184519 91177308-0d34-0410-b5e6-96231b3b80d8