[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at d915d40 Use ANSI escape codes for --use-color on Windows
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   d915d40..ef6f6d1  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to ef6f6d1c1a2819407c8c218119b97e1e656e5ef3.
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!