/usr/share/templates/.source/ is in libkonq5-templates 4:15.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/templates/.source/CAMERA-Device.desktop
/usr/share/templates/.source/CDROM-Device.desktop
/usr/share/templates/.source/CDWRITER-Device.desktop
/usr/share/templates/.source/DVDROM-Device.desktop
/usr/share/templates/.source/Floppy.desktop
/usr/share/templates/.source/HD.desktop
/usr/share/templates/.source/HTMLFile.html
/usr/share/templates/.source/MO-Device.desktop
/usr/share/templates/.source/NFS.desktop
/usr/share/templates/.source/Program.desktop
/usr/share/templates/.source/TextFile.txt
/usr/share/templates/.source/URL.desktop
/usr/share/templates/.source/ZIP-Device.desktop