v0.6.0

Added

• A --session option to use a separate QOwnNotes settings and database
  context, matching QOwnNotes' --session argument; the nix-run and
  nix-build-run Just recipes now use the test session by default.
• Ctrl-Space opens the link at the viewer cursor or toggles the checkbox at
  the cursor in the viewer and editor.
• Entering edit mode from the viewer keeps the cursor position and selection,
  and leaving the editor returns the cursor position to the viewer.

Changed

• Relicensed under GPL-3.0-only; the LICENSE file now contains the complete
  license text.