When running in development mode the plugin fails to initialise

[edmundg]

After running npm install then when running npm run dev an error is thrown in TypeScript when registering the debug panel.
This prevents the typescript application from transpiling.

[edmundg]

A simple fix for this is adding a new when registering the plugin:

if (process.env.NODE_ENV === 'development') {
    import("@melonjs/debug-plugin").then((debugPlugin) => {
        // automatically register the debug panel
       plugin.register(new debugPlugin.DebugPanelPlugin, "debugPanel");
    });
}