html/svg/xml elements
  reorder, delete, insert, rename, attributes, collapse, duplicate
  common types, custom types, known attribute names

css
  selector operators, known properties and values, custom ones...
  documentation for properties and values

typescript
  common symbols palette?
  likely symbol name autocomplete?
  select, copy/paste, delete, multi-cursor, indent, collapse
  typescript language server feedback, class documentation
  live transpilation and reload

live reload, serving
file browsing, password authenticated
git actions
can I list the ports of things currently being served?
maybe some kind of indication of server resource usage? ability to restart?