Release Notes:

- When `helix_mode = true`, modes are called without the `HELIX_` prefix
in the UI:
  `HELIX_NORMAL` becomes `NORMAL`
  `HELIX_SELECT` becomes `SELECT`
- (breaking change) Helix users should remove `"default_mode":
"helix_normal"` from their settings. This is now the default when
`"helix_mode": true`.