PDF export for timetables

Use PaperCSS and base_print.html template

changed title from PDF-Export für Stundenpläne to PDF export for timetables

changed the description

unassigned @hansegucker

added part::frontend type::feature workflow::confirmed labels

changed the description

added source::customer label

assigned to @ZugBahnHof

created merge request !77 (merged) to address this issue

mentioned in merge request !77 (merged)

assigned to @lloydmeins and unassigned @ZugBahnHof

closed with merge request !77 (merged)

mentioned in commit 577c6da3