Single line collapsed view

One nice feature we were looking for was to show the first few bytes of the json in a single line instead of just showing fully collapsed mode.

i.e

```
{
  "name": "Jack",
  "age": 10
}
```

Once liner view:

```
+ {"name": "Jack", "ag...}
```

And it can be controlled by a parameter to define how many bytes to show as default one liner.

Thanks.