Update fw_kobraOS.md

Author: 1coderookie

docs/firmware/fw_kobraOS.md

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+[![ko-fi](https://ko-fi.com/img/githubbutton_sm.svg)](https://ko-fi.com/U6U5NPB51)  
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 # KobraOS (Stock) 
 The official stock firmware for the **Kobra 2 Pro** is called "Kobra OS".  
 Even though it's based on Klipper, sources haven't been published yet.