Missing pseudo-classes

[connorshea]

I looked through vscode-css-languageservice's css-schema.xml and found a decent number of pseudo-classes that are missing from mdn/data.

• :blank
• :corner-present
• :current
• :current()
• :decrement
• :double-button
• :decrement
• :end
• :future
• :horizontal
• :increment
• :local-link
• :local-link()
• :matches()
• :no-button
• :nth-column()
• :nth-last-column()
• :nth-last-match()
• :nth-match()
• :past
• :recto
• :single-button
• :start
• :user-invalid
• :verso
• :vertical
• :window-inactive

Most of these are non-standard. I also excluded quite a few that are vendor-prefixed, not sure if they should be included.

This list is from my comment in this issue in vscode-css-languageservice.