docs: Prepare changelog for v0.19
docs: Prepare changelog for v0.19

pacificIT/mopidy,ali/mopidy,bencevans/mopidy,glogiotatidis/mopidy,mokieyue/mopidy,dbrgn/mopidy,kingosticks/mopidy,dbrgn/mopidy,woutervanwijk/mopidy,dbrgn/mopidy,quartz55/mopidy,hkariti/mopidy,jcass77/mopidy,mopidy/mopidy,jmarsik/mopidy,ZenithDK/mopidy,rawdlite/mopidy,jodal/mopidy,jcass77/mopidy,pacificIT/mopidy,jcass77/mopidy,tkem/mopidy,vrs01/mopidy,adamcik/mopidy,quartz55/mopidy,mopidy/mopidy,kingosticks/mopidy,bencevans/mopidy,glogiotatidis/mopidy,SuperStarPL/mopidy,diandiankan/mopidy,SuperStarPL/mopidy,swak/mopidy,diandiankan/mopidy,liamw9534/mopidy,hkariti/mopidy,bacontext/mopidy,liamw9534/mopidy,mokieyue/mopidy,pacificIT/mopidy,jmarsik/mopidy,jmarsik/mopidy,diandiankan/mopidy,bencevans/mopidy,jodal/mopidy,adamcik/mopidy,ali/mopidy,mopidy/mopidy,swak/mopidy,glogiotatidis/mopidy,swak/mopidy,ZenithDK/mopidy,rawdlite/mopidy,pacificIT/mopidy,jodal/mopidy,quartz55/mopidy,bacontext/mopidy,bencevans/mopidy,adamcik/mopidy,SuperStarPL/mopidy,mokieyue/mopidy,ZenithDK/mopidy,quartz55/mopidy,priestd09/mopidy,bacontext/mopidy,tkem/mopidy,swak/mopidy,kingosticks/mopidy,ali/mopidy,SuperStarPL/mopidy,vrs01/mopidy,rawdlite/mopidy,ali/mopidy,hkariti/mopidy,priestd09/mopidy,rawdlite/mopidy,vrs01/mopidy,woutervanwijk/mopidy,dbrgn/mopidy,mokieyue/mopidy,jmarsik/mopidy,vrs01/mopidy,diandiankan/mopidy,priestd09/mopidy,hkariti/mopidy,tkem/mopidy,glogiotatidis/mopidy,bacontext/mopidy,tkem/mopidy,ZenithDK/mopidy