Add a note about modifier.idf

> Note:
This model is supposed to be used with Qdrant. Vectors have to be configured with [Modifier.IDF](https://qdrant.tech/documentation/concepts/indexing/?q=modifier#idf-modifier).

README.md

@@ -10,6 +10,9 @@ Repository with files to perform BM25 searches with [FastEmbed](https://github.c
 
 ### Usage
 
+> Note:
+This model is supposed to be used with Qdrant. Vectors have to be configured with [Modifier.IDF](https://qdrant.tech/documentation/concepts/indexing/?q=modifier#idf-modifier).
+
 Here's an example of BM25 with [FastEmbed](https://github.com/qdrant/fastembed).
 
 ```py
@@ -34,5 +37,8 @@ embeddings = list(model.embed(documents))
 #                         1117393019
 #                     ]))
 # ]
+```
+
+
 
 ```