Possible types need more prominent place in documentation

Although this library is instantly sweet for the simplest of things copypasted from examples, I've spend quite some time trying to find *a list of supported format types.*

I've browsed through the documentation (where the search for 'types' returns nothing), googled around, tried to search through code in this repo, I just cannot find it.

So, even though this is probably very much my fault for not looking in the right place (can someone still tell me where I should look? :joy_cat: ), I think this list should have a more prominent position in the docs and in the README.md.

I'm new to this, and searching for possible format types is the first thing I'm doing with the docs. It is probable that other users will travel the same route.