add colab link

Author: nreimers

docs/pretrained_models.md

@@ -165,5 +165,5 @@ The following models apply compute the average word embedding for some well-know
 
 
 ## Image & Text-Models
-The following models can embed images and text into a joint vector space. See [Image Search](../examples/applications/image-search/README.md) for more details how to use it and how to embed images.
+The following models can embed images and text into a joint vector space. See [Image Search](../examples/applications/image-search/README.md) ([Colab Version](https://colab.research.google.com/drive/16OdADinjAg3w3ceZy3-cOR9A-5ZW9BYr?usp=sharing)) for more details how to use it and how to embed images.
 - **clip-ViT-B-32** - [OpenAPI CLIP Model](https://github.com/openai/CLIP)