Fix errors in docs

The model's HF id had an an extra "/" at the end preventing it to be downloaded automatically. The pymilvus installation instruction was also incomplete, missing the installation of the "model" component.

README.md

@@ -31,7 +31,7 @@ The model is compatible with Milvus Vector DB and is very easy to use:
 
 First, install the pymilvus library
 ```shell
-pip install pymilvus
+pip install pymilvus[model]
 ```
 
 The model can then be used to encode pairs of text and find the similarity between their representations
@@ -68,7 +68,7 @@ client.create_collection(
 )
 
 embeddings_model = model.sparse.SpladeEmbeddingFunction(
-    model_name="ibm-granite/granite-embedding-30m-sparse/", 
+    model_name="ibm-granite/granite-embedding-30m-sparse", 
     device="cpu",
     batch_size=2,
     k_tokens_query=50,