Document how to build docker images

mentioned in merge request !78 (merged)

changed milestone to %0.5.0

added Master Project 20/21 Theodolite Kotlin To Do modul/theodolite labels

mentioned in issue #206 (closed)

mentioned in merge request !116 (merged)

added In Progress label and removed To Do label

added Under Review label and removed In Progress label

removed Master Project 20/21 label

changed milestone to %0.6.0

mentioned in issue #204 (closed)

Fixed with !193 (merged)

closed