This commit updates the modelcard.template file used in the model
conversion scripts for embedding models to include the llama-server
--embeddings flag in the recommended command to run the model.
The motivation for this change was that when using the model-conversion
"tool" to upload the EmbeddingGemma models to Hugging Face this flag was
missing and the embedding endpoint was there for not available when
copy&pasting the command.
Recommended way to run this model:
```sh
-llama-server -hf {namespace}/{model_name}-GGUF
+llama-server -hf {namespace}/{model_name}-GGUF --embeddings
```
Then the endpoint can be accessed at http://localhost:8080/embedding, for