Add description/repostiory/readme to avoid npm warnings

/to @ritch @bajtos 
/cc @ijroth 

See https://github.com/strongloop/strong-arc/issues/748
A possibly better phrasing:

```
This is a project generated by [LoopBack](http://loopback.io).
```

or even

```
A project generated by [LoopBack](http://loopback.io).
```