[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 228f8d8 [llvm][NFC] Don't use llvm/Config/config.h in .h files
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   228f8d8..205e8b7  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 205e8b7e89e46e51909a3270b94f277a4c8863aa.
CMake Error at CMakeLists.txt:3 (cmake_minimum_required):
  CMake 3.13.4 or higher is required.  You are running version 3.7.1


-- Configuring incomplete, errors occurred!