Pass --watch to gatsby develop

[kevinsimper]

Just like you can do with jekyll serve -w you should be able to with Gatsby, so you don't have to restart gatsby by yourself when you create new routes.

[KyleAMathews]

As discussed on Discord, this is a known limitation of Gatsby. Whenever the issue is fixed, new routes will be hot reloaded along with everything else.

[kevinsimper]

I looked at it and I can't find any way to get notified whenever hot reload is applied, but if you could, you could fix this by running createRoutes again.

[kevinsimper]

I think this issue was close a bit too fast, since there is no other issue about the problem. If not I can't find it.

Here is an example on how it can be done:
https://github.com/glenjamin/ultimate-hot-reloading-example/blob/master/server.js