Revert "Add Save&Load section under FAISSDocumentStore"

This reverts commit 4466140.

docs/latest/components/document_store.mdx

@@ -63,36 +63,6 @@ from haystack.document_store import FAISSDocumentStore
 document_store = FAISSDocumentStore(faiss_index_factory_str="Flat")
 ```
 
-#### Save & Load
-
-FAISS document stores can be saved to disk and reloaded:
-
-```python
-from haystack.document_store import FAISSDocumentStore
-
-document_store = FAISSDocumentStore(faiss_index_factory_str="Flat")
-
-# Generates two files: my_faiss_index.faiss and my_faiss_index.json
-document_store.save("my_faiss_index.faiss")
-
-# Looks for the two files generated above
-new_document_store = FAISSDocumentStore.load("my_faiss_index.faiss")
-
-assert new_document_store.faiss_index_factory_str == "Flat"
-```
-
-While `my_faiss_index.faiss` contains the index, `my_faiss_index.json` 
-contains the parameters used to inizialize it (like `faiss_index_factory_store`). 
-This configuration file is necessary for `load()` to work. It simply contains 
-the initial parameters in a JSON format. 
-For example, a hand-written configuration file for the above FAISS index could look like:
-
-```json
-{
- faiss_index_factory_store: 'Flat'
-}
-```
-
 <div style={{ marginBottom: "3rem" }} />
 
 ### In Memory