Use cases of getElementsAtEventForMode are not documented

Documentation Is:

- Missing or needed

### Please Explain in Detail...
The documentation for getElementsAtEventForMode in https://www.chartjs.org/docs/3.5.0/developers/api.html#getelementsateventformode-e-mode-options-usefinalposition is following:

_Calling getElementsAtEventForMode(e, mode, options, useFinalPosition) on your Chart instance passing an event and a mode will return the elements that are found. The options and useFinalPosition arguments are passed through to the handlers.
To get an item that was clicked on, getElementsAtEventForMode can be used._

This doesn't tell me anything about what the options mean.

### Your Proposal for Changes

I found the documentation of the use cases from the history of migration documentation: https://github.com/chartjs/Chart.js/pull/7900/files
It has documentation on what options in the new function correspond the old functions, and the descriptions of the old functions is the only place that actually describes what the use cases are.

Can you please add the use case documentation for the getElementsAtEventForMode. Digging through version history is slightly not obvious.