The VSCode extension often gives error messages for conditions outside of its control, e.g. if the project `package.json` is malformed during a merge conflict. We should try to categorize the errors that may happen: * Errors from bugs in the extension * Errors from html-validate (internal errors) * Configuration errors in the users environment * Other environmental issues preventing the extension from running All of these should be handled separately and not all show the scary "The extension crashed" message.