v3.4.0

• [New] Shortcuts: Ctrl+W (close project), Ctrl+Q (quit), Ctrl+Alt+S (save all)
• [Fix] Markdown import maps heading levels to scene/group hierarchy
• [Fix] Warn before discarding unsaved timeline edits on close
• [Fix] Backups missing from Manage Backups
• [Fix] Spell-check crash
• [Fix] scene-tree flicker and performance
• [Fix] Allow Windows reserved names in scene/group titles
• [New] Server: Improved cryptography key management
• [Fix] Server: Reworked project URLs to fix 404s