[de] new rule "sang und klanglos" -> "sang- und klanglos", maybe not in the best category, but we had a similar rule already, so I put it here

git-svn-id: https://languagetool.svn.sourceforge.net/svnroot/languagetool/trunk/languagetool@9709 2fe6a88b-1217-0410-b804-ba6ed01314b8