Make available offline

• Make available offline: download entire books and shelves — pages stay readable without a connection
• Offline full-text search: finds downloaded content even in airplane mode, including match previews
• Spotlight: pages saved offline show up in iOS search and open right in the app
• Manage in Settings: an overview of your offline content with storage size and easy removal
• Demo server: try BookStax without your own installation using the official BookStack demo server — with a step-by-step guide
• Editor: the Markdown/visual editor switcher now has its own row and no longer overlaps buttons
• Smaller improvements and bug fixes