Add a way to get the pathing results from the last update call.

[andriyDev]

Fixes #8.

This isn't zero-cost. We could instead make this some sort of callback, but that would end up with mutexes and stuff in user code which is sad. I think this is a fine v1. We can always rework it in the future!

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 81.25000% with 6 lines in your changes missing coverage. Please review.

Project coverage is 98.3%. Comparing base (a3a1171) to head (e096c0c).

Additional details and impacted files

| [Files](https://app.codecov.io/gh/andriyDev/landmass/pull/36?dropdown=coverage&src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) | Coverage Δ | | |---|---|---| | [src/lib\_test.rs](https://app.codecov.io/gh/andriyDev/landmass/pull/36?src=pr&el=tree&filepath=src%2Flib_test.rs&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2xpYl90ZXN0LnJz) | `100.0% <100.0%> (ø)` | | | [src/lib.rs](https://app.codecov.io/gh/andriyDev/landmass/pull/36?src=pr&el=tree&filepath=src%2Flib.rs&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL2xpYi5ycw==) | `92.4% <76.0%> (-2.0%)` | :arrow_down: |