Add note to documentation re deep sleep

**Describe the problem you have/What new integration you would like**

Add a note like this to the deep sleep component page:
some devices, e.g. D1 mini, need GPIO7 pulled high for deep sleep to function currently. This post:
[[GeoX234](https://github.com/GeoX234) commented [on Mar 27](https://github.com/esp8266/Arduino/issues/6007#issuecomment-2024041618)] suggests connecting GPIO7/SD0/MISO via 10k resistor to 3.3v as a fix. This worked for me.

**Please describe your use case for this integration and alternatives you've tried:**

The device won't wake up from deep sleep, though there is a dim flash of the blue activity LED at the time it should wake up. soldering the 10k resistor causes wake up to run correctly.

**Additional context**

Open the ESPHome deep sleep component documentation page and review the referenced ESP8266 deep-sleep discussion. Add a concise note covering the affected devices, GPIO7/SD0/MISO, the 10k resistor connection to 3.3V, and the reported wake-up result; the page should clearly warn users about this hardware requirement.

Written by the indexing model from the issue text.