Project: expression-editor
Task (easy): On the left side of the toolbar, add a new button labeled "Run".
Upon clicking the "Run" button, use editor content as input for `evaluate` function in `evaluate.js`, and display the evaluate result below the editor.
- If the evaluate result is null, display "null".
- If the evaluate result is true, display "true".
- If the evaluate result is false, display "false".