Superficial docs for createRoot

[GiyoMoon]

The docs for createRoot lack some important information.

• Creating a root owner without accepting the dispose function in the callback creates an unowned root
• What are the differences between an owned and unowned root? (or link to a page mentioning this, if it's explained somewhere else)
• What is the detachedOwner property for? While there are typescript docs for it, it would still be very helpful to have some examples. It's currently not even mentioned in the docs.

This also applies to solidjs.com/docs.
Link to the current docs: https://docs.solidjs.com/references/api-reference/reactive-utilities/createRoot

[titoBouzout]

If you know the answer to these questions a PR for this file would be welcome https://github.com/solidjs/solid-docs-next/blob/main/src/routes/reference/reactive-utilities/create-root.mdx