Ensuring our API is similar to Web

Because we are "just building a browser" with LVN Core I want to ensure that we are matching the same API that exists on the web, in other words if we are exposing analagous functions to clients tha would exist within a browser we should be exposing the same fucntion name. Examples:

* `document` - should expose the underlying document
* `document.querySelector(selectors)` - for querying the document

Our mission is to ensure we are providing a new yet familiar experience. We are building on top of existing knowledge that developers have about how a web browser works but we are swapping out certain parts of that stack. LVN's role is to be the foundational piece of this.

Start by reviewing the existing LVN Core client-facing API and the browser equivalents named here: document and document.querySelector(selectors). Define which analogous functions are in scope and establish naming and coverage criteria. Done means the supported surface and missing APIs are specified and agreed.

Written by the indexing model from the issue text.