[FEATURE] Plugin hook to execute command after the server start

[aelbore]

The problem that you want to solve. A quick, clear and concise description of what the problem is. Ex. I'm always frustrated when [...] Plugin hook to execute any command or code after the server start, in vite they have (configureServer) https://vitejs.dev/guide/api-plugin.html#configureserver

Your take on the correct solution to problem.

Are you willing to submit a pull request to implement this change? Maybe but not familiar with the snowpack codebase

[FredKSchott]

• You can run a command in the run hook, which runs when the server or build starts.
• you can add a routes entry to configure custom dev server routes

• 3030 was created to add the ability to modify requests/headers from the server