[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at ee142c4 [llvm-objcopy] Make --set-section-flags work with --add-section
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   ee142c4..d0d43b5  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to d0d43b58b109c2945e30d0bfabe77d3dcf1e4ad5.
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!