doc: mention privacy error in Chrome for development

doc/development.md

 ```
 
 The app should be running at https://localhost:8080/
+
+#### Chrome Privacy Error
+
+Newer versions of Chrome may block localhost under https and show `NET::ERR_CERT_INVALID` on the page. To solve this open [chrome://flags/#allow-insecure-localhost](chrome://flags/#allow-insecure-localhost) and select Enable, then press Relaunch or quit and restart Chrome.