Code action bindings

[jfaz1]

There should be a way to bind code actions directly onto keys.

VS Code allows for this in the following way:

{
  "key": "ctrl+shift+r ctrl+e",
  "command": "editor.action.codeAction",
  "args": {
    "kind": "refactor.extract.function"
  }
}

I'm working on a Markdown LSP, and one of the code actions I have is checking/unchecking a task. Would be nice to be able to bind directly to a key.