npm start build stuff and is too slow

Nadie ha tomado este issue todavía.

On a project made with the cli npm start launch the following command:

` "start": "node -r source-map-support/register .",`

This basically clean and build the full project and then start it in a dev mode.

This command can take forever to run. Azure App Service ping app and has a 230 timeout before they shutdown the container. On a small instance, the container will be shutdown before loopback has a chance to start. It's anyway a waste of ressource has Azure run build (in the build process, so no timeout) and then start (in startup script).

I belive npm start should run `"start": "node ./dist/index.js",` instead. A specific command for dev could be introduced such as `"dev": "npm run build && node -r source-map-support/register .",`.

Those are my current scripts:
```
"scripts": {
"build": "npm run clean & npm run copy-files && lb-tsc",
"build:watch": "lb-tsc --watch",
"pretest": "npm run build",
"migrate": "npm run build && node ./dist/migrate",
"openapi-spec": "npm run build && node ./dist/openapi-spec",
"dev": "npm run build && node -r source-map-support/register .",
"start": "node ./dist/index.js",
"clean": "lb-clean dist *.tsbuildinfo .eslintcache",
"copy-files": "mkdir -p dist && cp -r ./backend ./src/data ./dist"
},
```

Empieza con los scripts npm del proyecto mostrados en el issue e inspecciona cómo se inicia la CLI desde la salida dist compilada. Haz que npm start inicie el punto de entrada compilado sin volver a compilar, conserva un comando de desarrollo para el comportamiento de compilación y ejecución, y verifica que ambos comandos mantengan sus funciones previstas.

Escrito por el modelo de indexación a partir del texto del issue.