docs-bug(slider): Clarify doc description of ability for range sider thumbs to overlap

[stephanietuerk]

Documentation Feedback

The Slider docs in the Selecting a range section may benefit from some clarification. Currently the documentation states that:

Each of the thumbs has an independent value, but they won't be allowed to overlap

but very clearly the two thumbs in a range slider can be positioned to have the same value.

I'm not sure what is intended by "they won't be allowed to overlap," but to me this is confusing text given the behavior.

Affected documentation page

https://material.angular.io/components/slider/overview#selecting-a-range

[DenisRudiy]

Think of it as a kind of two values, min and max. You can set two values, but only in such a way that min <= max. Hence it's as if you are controlling a range of numbers, which allows you to set such ranges:
[2-5], [144-145], [5-5]

[stephanietuerk]

@DenisRudiy Thanks, that's a helpful explanation. I can open a PR to improve the docs with that -- I don't feel like the term "overlap" is sufficiently precise in the current docs.