Make sure all boxes are checked (add x inside the brackets) when you submit your contribution, remove this sentence before doing so.
-[ ] This PR is compliant with the [contributing guidelines](https://github.com/nodemcu/nodemcu-firmware/blob/dev/CONTRIBUTING.md)(if not, please describe why).
- [ ] I have thoroughly tested my contribution.
- [ ] The code changes are reflected in the documentation at `docs/en/*`.