add PlantPhotoAI (#124)

* add PlantPhotoAI

* add plants

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Co-authored-by: Steven Van Vaerenbergh <[email protected]>

Author: layerzzzio

DISCOVERIES.md

@@ -136,6 +136,7 @@ Before submitting your suggestions, please review the [Contribution Guidelines](
 - [Picwish](https://picwish.com/) - Use PicWish AI photo editor to remove background, unblur image, and do more image editing.
 - [Human Generator](https://generated.photos/human-generator/) - Create hyperrealistic full-body photos of people in real time.
 - [LogoGPT](https://chatgpt.com/g/g-z61XG6t54-logogpt) - Designs personalized logos from sketches.
+- [PlantPhotoAI](https://www.plantphotoai.com/) - Free AI-generated plant photos with botanical accuracy.
 
 ### Graphic design