[Keyboard] add Little Keyboards as a seller of helix pcbs outside of japan (#7249)

* add lkb as a seller of helix pcbs outside of japan

* Update keyboards/helix/readme.md

keyboards/helix/readme.md

@@ -7,7 +7,7 @@ A compact split ortholinear keyboard.
 
 Keyboard Maintainer: [Makoto Kurauchi](https://github.com/MakotoKurauchi/) [@pluis9](https://twitter.com/pluis9)  
 Hardware Supported: Helix PCB Alpha, Beta, Pro Micro  
-Hardware Availability: [PCB & Case Data](https://github.com/MakotoKurauchi/helix), [Yushakobo Shop](https://yushakobo.jp/shop/)
+Hardware Availability: [PCB & Case Data](https://github.com/MakotoKurauchi/helix), [Yushakobo Shop](https://yushakobo.jp/shop/), [Little Keyboards](https://littlekeyboards.com/collections/helix) 
 
 Make example for this keyboard (after setting up your build environment):