Fix missing generator on Windows
Fix missing generator on Windows

- Since compiler is not listed on settings, CMake is not
  able to detect a valid generator, using MingGW by default
- Add topics to be used as tags for searching

Signed-off-by: Uilian Ries <d4bad57018205bdda203549c36d3feb0bfe416a7@gmail.com>

ColinH/PEGTL,ColinH/PEGTL