[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at aca191c Re-land 7a527f17776be78ec44b88e82b39afb65fc148e4 with fixes.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   aca191c..5e3fd47  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 5e3fd471acb7fb01514b55bd24522da099a7b97c.
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!