[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 8839e27 [Modules] Improve error message when cannot find parent module for submodule definition.
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   8839e27..1d1515a  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 1d1515a9e28c7f32af548584ebed66cd8caae84f.
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!