Fix ex1_basic_usage demo

#503

use .instant('SERVICE') instead of ('SERVICE')

```
  <!-- Using a $translate service -->
  <p>{{jsTrSimple}}</p>

  <!-- Passing a data to the $translate service -->
  <p>{{jsTrParams}}</p>
```

display:
```
{}

{}
```

instead of:
```
Of course, you can translate your strings directly in the js code by using a $translate service.

And you are still able to pass params to the texts. Static = #, random = #.
```