Add some sample MT configs

[ValarDragon]

Currently its a bit hard to use the MT's in this library. Would be really useful if we could have some out-of-the-box MT configs that people can use to get started with, when hacking on new projects.

I think we could do this by having a second feature flag called "examples", which if enabled, lets you import some example configs. (And then you also know where to look to copy/paste examples)

We basically do this already in private for testing, so would be great to get it exported.

[Pratyush]

The tricky part for example configs is that they enable the corresponding curve/field dependencies

[burdges]

You could initially do an unpublished examples crate form which people could cut n paste what they like. It might not stay that way but it maybe easier to choose between features and micro crates once you see the final code.