Support engine configuration

[mchugh19]

As discussed in #228

[mchugh19]

Using jinja filters like {{ engines | yaml(False) | indent(2) }} makes this very simple. Perhaps deceptively simple?

If this style works for everyone, a bunch of manual templating work could be saved.

[herisanu]

I would say +1 to the jinja filter above. We use it a lot and it didn't cause any problems (once you find out the correct indent number).

[gravyboat]

I don't see any issue with the filter. Especially considering that it's a new addition we don't have to worry about breaking backwards compatibility. Thanks!