Description

Creates a new lint that detects when an element is unknown to it's parent's content-model.

Motivation and Context

Helps user's discover when they accidentally break the document's content-model

How Has This Been Tested?

• Unit tests
• w3c
• lsp in Helix

Types of changes

Fixes

• Fixes Element::parent_element returning Some when parent is a document node
• Fixes aliased elements being parsed as ElementId::Unknown instead of ElementId::Aliased

Features

• Adds new lint

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.