TLDR:

• new map tool with pins, regions, paths, labels, measuring, fantasy navigation, and multiplayer cursors
• New project filter tool and multi-select in the left sidebar
• Global tag management in the LK menu. (rename & delete)
• New asset manager with Unsplash and Pinterest integration
• Map embed block for pages and the right sidebar
• Emoji overhaul

The long version:

• A brand new map tool!
  • Pins
    • Control whether the pin label is hover, always, or never show.
    • Hold Ctrl while using pin tool to snap to paths and regions.
  • Regions
    • Create regions with fill style, stroke style, text labels, etc.
    • See area and perimeter of region when map is calibrated.
    • Border-borrow: Use Ctrl when making a region to snap to the border of another region. Close a region along another regions border to automatically use the border.
  • Paths
    • Catalog roads, paths, etc. with styled roads.
    • Dynamically display path labels at various zooms, much like Google Maps.
    • See length of path when map is calibrated.
    • Hold Ctrl to snap.
  • Labels
    • Create text labels with different colors, fonts, and sizes
  • Measuring
    • Calibrate your map by measuring and providing a distance in miles or kilometers.
    • Re-use that distance for measurements using the measure tool.
    • Once calibrated, your map shows a dynamic, accurate range key in the bottom left.
  • Zoom Visibility controls
    • Control which map layers show at what zoom levels, enabling you to make stylish zoom-dynamic maps.
  • A new Map Toolbar
• Pin tool, text tool, region tool, path tool, measure tool
• Keyboard shortcuts
• Tool Lock mode, to rapidly drop pins, make paths, etc. 
• A new visual pin editor that doesn’t interrupt your flow
  • Customize label display rules for most things
• A large variety of style rules for all map layer types.
• The Link section of the pin editor auto-fills the Link Existing flow if the pin has name match with a page from your world.
• New map layer right-click context menu
  • Use menu to easily link unlinked layers pins/regions/paths/labels.
  • Use menu to easily unlink map layers.
  • Use mini swatch picker to quickly customize colors.
• Multi-select
  • Hold shift to box-select multiple items on the map.
  • Mass edit map objects to change their colors and styles.
• A new map sidebar (with multi-select)
  • Style your pins, regions, labels, and paths before you drop them in.
  • Nest your map layers into groups
  • Pins will favor clustering into hierarchical groups when available
  • Multi-select with shift and ctrl to move and delete pins en masse.
  • Right click a group to hide/solo a map layer group.
  • New finder field that lets you filter your pins by name and tags
• Navigation using paths
  • Activate navigation mode on map to see traveling directions that incorporate path names, landmarks via pins, etc.
  • Customize travel speed to see how long a journey might take. 
• Undo-redo
  • The map now supports undoing and redoing most actions with Ctrl-Z and Ctrl-Shift-Z. 
• Map Multiplayer
  • Map now shows multiplayer cursors, like wiki pages and boards.
• Duplicate map objects using Ctrl+D or context menu.
• A powerful new right-click radial menu that lets you access your four new map tools quickly.
• Pins must be selected to be dragged, eliminating accidental drags while panning.
• Pins now make a “plop” sound when you drop them. Disable sounds in LK menu.
• Unified public view and private view with same map engine.
• A brand new WebGL powered rendering engine that can display many more pins smoothly
• Sidebar image block height can now be customized.
• New map block
  • Embed maps into your pages and right-sidebar.
  • When a map block detects a pin for the host page, auto-centers on that pin on the map.
  • Press Edit button to otherwise customize the viewport for the map block.
  • Quickly navigate to map via the Open button.
• Improvements to project browser
  • New finder bar:
    • Filter your pages by both name and tags.
    • Click filter button or type # to quickly filter by tags.
    • Otherwise type to filter by name.
  • Redesigned sidebar with a more consistent design.
  • Project sidebar now supports multi-select
    • Multi-select using shift and ctrl to mass-move, mass-hide, and mass delete project pages.
  • Project sidebar now has new modes:
    • Assets tab (see details below)
    • Map tab (when viewing a map)
  • Search button moved to top center of top bar. 
• New assets sidebar
  • A new way to engage with your files via your project sidebar, in addition to the assets dialog.
  • View your assets as a grid or list in the sidebar.
  • Easily search your files and drag and drop images into your project.
    • Drag images to property bar to make image property.
    • Drag images into articles to insert images.
    • Drag images into banner to quickly set banner.
  • New third-party asset integrations that support drag and drop image operations:
    • Unsplash.com for easily finding stock images to use in your projects.
    • Pinterest.com to easily wire up LegendKeeper to your Pinterest boards. 
• New global tag manager
  • See an overview of all tags in your project
  • See usage count of each tag in your project
  • Mass-rename and mass-delete tags across your project.
• Emoji overhaul
  • For consistency across platforms, standardized emojis via Twemoji, a Creative Commons emoji set that’s used by Discord and many other platforms.
  • No more layout and size differences between emojis across operating systems.
  • Reduced the size of the emoji set; extremely rare emojis may not render properly anymore. We can add emojis back by demand (we’ll have to design the emojis ourselves though, so keep that in mind.)
• Moved global Search function to central, top position in app.
• App UI polishing
  • Tweak padding and visual clustering
  • Tweak font sizes and colors for readability and cognitive load.