add URLs for dependencies

Author: rhysd

doc/textobj-function-clang.txt

@@ -48,6 +48,14 @@ them by writing below code in your vimrc.
         \   }
         \ }
 <
+- textobj-user
+https://github.com/kana/vim-textobj-user
+
+- textobj-function
+https://github.com/kana/vim-textobj-function
+
+- libclang-vim
+https://github.com/rhysd/libclang-vim
 
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 LICENSE						*textobj-function-clang-license*