[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 9e3b4f4 [JumpThreading] Make -print-lvi-after-jump-threading work with NPM
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   9e3b4f4..9d77584  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 9d77584fe04010a2aa536308d4032bf5677d7000.
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!