[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 84048e2 [format] foo.<name>.h should be the main-header for foo.<name>.cc
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   84048e2..229db36  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 229db3647491ed2b2706a9b9ce13a97e38be6fa0.
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!