Requesting a new app: Josm

[M-Rick]

Requesting a new app ✨

If you are requesting a new app to be added to deb-get please complete the
following section, only one app per issue please.

• I have checked that this app does not already have a pending request and has not previously been declined.
• App Name: Josm
• Download URL: https://josm.openstreetmap.de/apt/pool/universe/j/josm/josm_1.5.svn18969_all.deb
• Website URL: https://josm.openstreetmap.de/
• App Summary: JOSM is an extensible editor for OpenStreetMap (OSM) for Java 11+.
  It supports loading GPX tracks, background imagery, and OSM data from local sources as well as from online sources and allows to edit the OSM data (nodes, ways, and relations) and their metadata tags.

wget -q https://josm.openstreetmap.de/josm-apt.key -O- | sudo apt-key add - 
sudo add-apt-repository --yes "deb https://josm.openstreetmap.de/apt $(lsb_release -c -s) universe"