D12995: add basic kdiff3 man page

[Michael Reeves]

mreeves added a comment.


  I'll have a look at the kf5 options.

REPOSITORY
  R983 KDiff3

REVISION DETAIL
  https://phabricator.kde.org/D12995

To: lueck, mreeves, #documentation
Cc: ltoscano, kde-doc-english, skadinna