message: Add formatOnSave to settings.json
diff: "**/.DS_Store": true,
  "**/*.bk": true,
  },
  + "[rust]": {
  + "editor.formatOnSave": true
  + },
  "rust-client.channel": "nightly-2018-02-28",
  "rust.unstable_features": true,
  "rust.workspace_mode": true,
  