Add support for `onscrollsnapchanging` and `onscrollsnapchange` events

[korywka]

Describe the problem

https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollsnapchange_event
https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollsnapchanging_event

Describe the proposed solution

Add to types:

svelte/packages/svelte/elements.d.ts

Line 85 in 2342c87

export interface DOMAttributes<T extends EventTarget> {

Importance

nice to have

[Conduitry]

I don't know whether we have an official stance on this, but adding types for an experimental feature that's only available in one of the three big browser engines feels iffy to me.

[korywka]

Can this issue remain open while we wait for Firefox or Safari support? I believe the wait won't be too long.

[dummdidumm]

We have not added experimental types in the past and we should keep it that way. If you want to you can extend the types yourself as explained here https://svelte.dev/docs/svelte/typescript#Enhancing-built-in-DOM-types

Keeping this open so we can revisit once it's stable