Whenever you create a new route or directive, you have to use
control+c in your grunt terminal window to quit the grunt process and re-run
grunt serve for your new route/directive to be included in your project’s index.html. Sometimes grunt can be a little finnicky and refuses to run if it thinks something is wrong with your project. Obviously you should try to fix the problem, but grunt’s errors aren’t very helpful so don’t worry too much–grunt usually will still run totally fine with the command
grunt serve --force.