v3.0.1 - Maintenance release

This is a maintenance release with no code changes

• Updated all NPM packages
• Renamed app.d.ts to svg.d.ts since Svelte doesn't like these typings in
  app.d.ts (see issue 25)
• Also copy svg.d.ts to dist/ on build.
• Some fixes to the README file
• Thanks to @joakimnordling for PR #35