[translations] German docs for 2.12.x

[Till Paala <till.rettig@xxxxxx>]

Hi John,

I discovered that chapters 4 spacing and 5 changing defaults are not 
translated to German for the last 2.12 version though I have translated 
them last summer and thought they have been included. What is happening 
here? According to the git repository the files are normally included 
into lilypond.tely. Do you have any ideas?

Greetings
Till