v0.2.0

Added

• ctx.res.markForDownload() helper.
• naddder.useMiddleware(callback) registers route-inspecific callbacks, always
  called after any available route handlers.
• Document wrapper for JSX pages (inc. doctype, head, and body markup and
  class transformation with Uno CSS).
• WebSocket connections can be grouped into channels for message broadcasting.

Changed

• Replaced the Windi CSS engine with
  an Uno CSS engine.
• Response helpers are built into ctx.res.
• WebSocket connections are established by upgrading a route handler,
  instead of requiring their own separate handler.

Fixed

• JSX now handles 0 and false values properly.
• The Session interface is exported.