MutationObserver perfomance and Narrowing actually used text nodes

[FrameMuse]

Problem

Mutations

We want to watch for any changes in elements to handle a possibility of elements that they changed their position or bounds.

For this we use MutationObserver, which is observing everything starting from root element.

If we let to pass any node to the root, it may contain unwanted elements, which may be the Editor elements themselves. So we need to check if a mutation doesn't relate to any of unwanted elements, which may be harmful for perfomance since it should be checked on every mutaiton callback.

Unrelated elements

Custom root element may also contain, elements, which are not localized by i18next, which may be misleading to highlight them. It's also harmful for perfomance since we need to observe for changes of elements are not actually related to the Editor.

Solution

• Split (and isolate) the Editor elements and root elements.
• Add a wrapper element to root elements, which will be root element.

[FrameMuse]

Related to #27

[FrameMuse]

Updating due to #57, now will be work using createPortal and DocumentFragment without creating a div with all: inherit style.