Clearify the README.md

[sonite]

Great Work, thanks!

Is it possible to improve the README.md by adding that later versions of ESP8266 DOWNLOAD TOOL, like 3.9.5 won't allow the user to set FLASH SIZE. It detects my old NodeMCU as a 4MB and that's it.

Older version like V.3.6.6 detects it as 32Mbit and works with the recommended settings of 80MHz/DIO/8Mbit.

[martin-ger]

What text would you suggest?

[sonite]

Perhaps:
On Windows you can flash it using the "ESP8266 Download Tool" available at https://espressif.com/en/support/download/other-tools. Download the two files 0x00000.bin and 0x02000.bin from the firmware directory. For a generic ESP12, a NodeMCU or a Wemos D1 use the following settings (for an ESP-01 change FLASH SIZE to "8Mbit"). We've observed that certain recent editions of the "ESP8266 Download Tool," such as version 3.9.5, prevent users from configuring the correct FLASH SIZE, resulting in the ESP being flashed with incorrect settings: