Out of Box solution for zoom in/out text only:
1. Ctrl + Shift + P (or View -> Command Palette....)
2. Type Open User Settings
3. Edit Settings.json
4. Add "editor.mouseWheelZoom": true
5. Save it.
결론은 설정에 들어가서 추가해 주면 된다.
"editor.mouseWheelZoom": true
