npm start build stuff and is too slow

Personne n'a encore pris cette issue.

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"
},
```

Commencez par les scripts npm du projet présentés dans l’issue et examinez comment la CLI démarre à partir de la sortie dist générée. Faites en sorte que npm start lance le point d’entrée généré sans effectuer de nouvelle compilation, conservez une commande de développement pour le comportement de compilation et d’exécution, et vérifiez que les deux commandes conservent leurs rôles prévus.

Rédigé par le modèle d'indexation à partir du texte de l'issue.