[www-scripts] Clang Attribute Doc Update: ERROR

[root via www-scripts]

UPDATING LLVM SOURCES
HEAD is now at 010d7a3 [lldb/test] Catch invalid calls to expect()
>From https://github.com/llvm/llvm-project
 * branch            master     -> FETCH_HEAD
   010d7a3..477a687  master     -> origin/master
First, rewinding head to replay your work on top of it...
Fast-forwarded master to 477a68760b24f07a45253fb41e89368328b3a4a8.
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!