typo: Embeddint -> Embedding (#322)

Author: ravi77o

tutorials/39_Embedding_Metadata_for_Improved_Retrieval.ipynb

@@ -284,7 +284,7 @@
     "\n",
     "We will then be able to compare the results and see if embedding metadata has helped with retrieval in this case.\n",
     "\n",
-    "> 💡 Here, we are using the `InMemoryEmbeddintRetriever` because we used the `InMemoryDocumentStore` above. If you're using another document store, change this to use the accompanying embedding retriever for the document store you are using. Check out the [Embedders Documentation](https://docs.haystack.deepset.ai/v2.0/docs/embedders) for a full list"
+    "> 💡 Here, we are using the `InMemoryEmbeddingRetriever` because we used the `InMemoryDocumentStore` above. If you're using another document store, change this to use the accompanying embedding retriever for the document store you are using. Check out the [Embedders Documentation](https://docs.haystack.deepset.ai/v2.0/docs/embedders) for a full list"
    ]
   },
   {