Integrate `geo` to gain algorithms

[RobWalt]

While it's cool that the crate itself doesn't have many dependencies, we would potentially need to implement a lot of algorithms on our own if we stuck to only depending on geo-types. Also, this crate here is used:

• as a debugging crate in many use cases anyways
• used in conjunction with geo in many use cases anyways

Because of this, I think it's not a big issue if we depend on geo directly (with default features turned off!). I'm planning on implementing PolyLabel in geo which would be one of the cool algorithms we could utilize here then.

[urschrei]

Is there any reason you can't pull in PolyLabel? I think the only dependency it doesn't share with geo is libc, and I can easily feature-gate that since it's only for FFI. I've wondered about integrating into geo before and decided that it was somewhat too specialised, so we wouldn't accept duplicate functionality.

[RobWalt]

Oh I totally forgot to do the obvious thing first: searching on crates.io 😅

I found your repo and I'll just use it as suggested 👍