* CSS was created to reduce re-specifying design styles: specify table cell

* CSS was created to reduce re-specifying design styles: specify table cell
  color once at the top, and do not repeat it 82 times
* Replace bright blue table border with gray, which is easier on the eyes and
  matches the gray LLVM documentation color scheme

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16175 91177308-0d34-0410-b5e6-96231b3b80d8