Update README.md

Author: tapio

README.md

@@ -147,6 +147,7 @@ Version history
 - HTTPS configuration now also accepts a plain object (@pavel)
 - Move `--spa` to a bundled middleware file
 - New bundled `spa-no-assets` middleware that works like `spa` but ignores requests with extension
+- Allow multiple `--open` arguments (@PirtleShell)
 * v1.1.0
 - Proxy support (@pavel)
 - Middleware support (@achandrasekar)