ClangFormat.rst: improve formatting


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172007 91177308-0d34-0410-b5e6-96231b3b80d8
ClangTools.rst: spelling and formatting


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@172008 91177308-0d34-0410-b5e6-96231b3b80d8