herdr-estate v0.3.0

- Tested against herdr 0.9.3, which changes none of the commands,
  replies or paths the plugin uses. It still needs herdr 0.9.1 or later.
- A new workspace now puts herdr's workspace list in label order: `~`
  first, the rest ignoring case. The manifest runs the new `sort` verb
  on herdr's `workspace.created` event; it moves only the workspaces out
  of place, and a move herdr refuses is logged and the rest left as is.
- Sort spaces runs the same sort on demand: a row at the foot of the
  picker (type `sort` to reach it), which keeps the picker open and
  shows what it did, and the manifest action `herdr-estate.sort` for a
  key binding.