Add translation for discussion composer title
Add translation for discussion composer title

Extracts "Start a Discussion" into a reference variable

pladask/flarum-ext-norwegian-bokmal,ogioncz/flarum-ext-czech,pladask/flarum-ext-norwegian-bokmal,FlarumChina/flarum-ext-simplified-chinese-pro,balkanje/flarum-ext-bosnian1,flarum/english,gtugablue/flarum-ext-portuguese,raweba/flarum-ext-danish,flarum/flarum-ext-english,FlarumChina/flarum-ext-simplified-chinese-pro,ogioncz/flarum-ext-czech,pladask/flarum-ext-norwegian-nynorsk,pladask/flarum-ext-norwegian-nynorsk