Make it more obvious to the developer when the server needs to be restarted

[danielbachhuber]

While working on https://github.com/Automattic/studio/pull/497, I was confused at times on why my changes weren't being applied. As it turns out, any changes to the Node server files (e.g. https://github.com/Automattic/studio/pull/497/files#diff-eb193b2da1aa77c2b5b32588db5da8fbc06580ee0de1e0cec4f30893bec6f604R300-R324) require a server restart.

We include some mention of this, but it's not obvious unless you already know where to look.

We should make it more obvious to the developer when they're making changes to a file that require a server restart (or we should just restart the server automatically).