Project: expression-editor
Task (moderate): On the right side of the toolbar, and before the `Documentation` button, add a new button labeled "Insert Snippet".
Upon click the `Insert Snippet` button:
- Ensure that the editor remains focused (meaning the cursor continues to blink within the editor) if it was initially focused.
- The content "true OR false" will be inserted at the cursor's current position or replace the selected text in the editor. If the editor is not focused, insert the content at the end of the editor.
- Considering that users may need to delete newly inserted text, the new text should be selected after insertion.