[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at b7448a3 [Attributor][NFC] Use indexes instead of iterator
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   b7448a3..160c133  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 160c133be5e12899e7c86af9604bddd08a9a2681.
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!