Fixed misleading binding in usage example snippet

[Hejtmus]

Hello @janosh,

great library. Yesterday when I discovered it, I wanted it to test it before using, and I discovered small inconvenience. Example code has incorrect binding in it, which is perfectly fine, but not if you are experimenting with a lot of libs in bulk, and you just want to see whether reference implementation of some lib works within your project. Obviously, when you are choosing library, you read it's source code, but I personally like to blind test it, and then later dig through docs and source. When I blind copied reference implementation, it didn't work, and I had to debug it, to find out that reference implementation is actually pseudocode. So I think that this little change could save some devs time :).

Best regards,
Filip.

[janosh]

Thanks, doc improvements are always appreciated! Needed to do some housekeeping anyway.