feature: add unit option to nearest-point

[mwenko]

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Feature description

• The nearestPoint function does not allow to specify the units option. It uses under the hood the distance function, that accepts such an option. This change adds that option as optional to the nearestPoint() function.
• This allows to specify the unit you wanna have returned in the result properties.distanceToPoint
• This saves the conversion step of a caller that needs the value in a different unit than kilometers (which is the default)

Tests

• A test case was added and succeeds.

[JamesLMilner]

@mwenko this seems like a nice improvement and think it is a good candidate for merging.

Can I request two small changes:

• Can you update types.ts to include the units option. So basically this line goes from:

const nearest = nearestPoint(targetPoint, points);

to:

const nearest = nearestPoint(targetPoint, points, { units: "kilometers" });

• Can you please run npm run docs to update the docs

After this I think I can approve

[mwenko]

@mwenko this seems like a nice improvement and think it is a good candidate for merging.

Can I request two small changes:

• Can you update types.ts to include the units option. So basically this line goes from:

const nearest = nearestPoint(targetPoint, points);

to:

const nearest = nearestPoint(targetPoint, points, { units: "kilometers" });

• Can you please run npm run docs to update the docs

After this I think I can approve

@JamesLMilner
Thanks for reviewing!
I updated the types & docs. Let me know if there is anything left.

[rowanwins]

Looks really good @mwenko - just one final little thing and then we'll merge :)