Add velocity measurement to radar example

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 0% with 6 lines in your changes missing coverage. Please review.

Project coverage is 94.12%. Comparing base (aa4b0e5) to head (0422f65).

Files	Patch %	Lines
crates/minikalman/src/kalman/extended.rs	0.00%	6 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #33 +/- ## ========================================== - Coverage 94.21% 94.12% -0.10% ========================================== Files 43 43 Lines 6261 6267 +6 ========================================== Hits 5899 5899 - Misses 362 368 +6 ```

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