docs: Canonicalize URLs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129181 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/ExtendingLLVM.html b/docs/ExtendingLLVM.html
index 647fa01..df706ea 100644
--- a/docs/ExtendingLLVM.html
+++ b/docs/ExtendingLLVM.html
@@ -382,7 +382,7 @@
   <a href="http://validator.w3.org/check/referer"><img
   src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
 
-  <a href="http://llvm.org">The LLVM Compiler Infrastructure</a>
+  <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a>
   <br>
   Last modified: $Date$
 </address>