Allow for multiple instances

[gtek1]

Can you please add documentation and/or an example on how to run multiple instances on a single page?

[S1SYPHOS]

@callmecavs thanks for this library, an example as requested would be most helpful, since whenever I'm trying to do this, I'm ending up with the second instance causing container is null, see #61

[S1SYPHOS]

Since I couldn't get around this issue, I'm going for another library. It's a shame though 😕