Clarify that this component uses voltage range at the chip pin, but voltage range at the board pin can be greater (e.g., for NodeMCU)
## Description:
**Related issue (if applicable):** fixes <link to issue>
**Pull request in [esphome](https://github.com/esphome/esphome) with YAML changes (if applicable):** esphome/esphome#<esphome PR number goes here>
**Pull request in [esphome-core](https://github.com/esphome/esphome-core) with C++ framework changes (if applicable):** esphome/esphome-core#<esphome-core PR number goes here>
## Checklist:
- [ ] Branch: `next` is for changes and new documentation that will go public with the next ESPHome release. Fixes, changes and adjustments for the current release should be created against `current`.
Co-authored-by: Otto Winter <otto@otto-winter.com>
