[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 4dde325 [clang-tidy] Fix build for gcc5.3 after d725f1ce
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   4dde325..45ddb24  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 45ddb245c50c2f3a109ad22174e9b52ad6de0ac7.
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!