This release introduces two huge new features

• Validation for HTML elements and attributes (including nesting, attribute values and combinations, etc).
• All the main LSP features: completions, polished autoformatting, definitions, etc.

SuperHTML is as of today the only HTML language server that implements the WHATWG HTML living spec to this degree (see open issues for the last few remaining bits).

Detailed changelist:

• All major Language Server features implemented: completions, clear diagnostics, descriptions, etc.
• New diagnostics cover element nesting errors and attribute validation, including complex interactions between different attributes and elements.
• Duplicate ID diagnostics that are <template> aware.
• Rename symbol on a tag name will rename both start and end tags at once.
• Find references can be used on class names to find other elements that have the same class.
• New improved autoformatting that keeps the first attribute on the same line as the element:
  • Uses tabs for indentation and spaces for alignment (experimental, might be reverted)
  • Respects empty lines that delineate separate blocks.
  • Doesn't format vertically elements in between text nodes anymore.
  • Basic CSS and JS autoformatting.
• Introduced a "Syntax Only Mode" setting to disable advanced validation for compatibility with templated HTML files.

This is a huge jump forward bug reports (with repro instructions!) are appreciated. If you believe a diagnostic produced by SuperHTML to be wrong you are welcome to open an issue but you will be asked to reference the HTML spec to dissuade poorly researched, drive-by issues.