Add lancedb-haystack to integrations. (#238)

* Add lancedb-haystack to integrations.

* Apply correct label install codeblock, add logo, and add link to API docs.

integrations/lancedb.md

@@ -0,0 +1,69 @@
+---
+layout: integration
+name: LanceDB Haystack
+description: A DocumentStore backed by LanceDB
+authors:
+    - name: Alan Meeson
+      socials:
+        github: alanmeeson
+pypi: https://pypi.org/project/lancedb-haystack/
+repo: https://github.com/alanmeeson/lancedb-haystack
+type: Document Store
+report_issue: https://github.com/alanmeeson/lancedb-haystack/issues
+logo: /logos/lancedb.png
+version: Haystack 2.0
+toc: true
+---
+### **Table of Contents**
+- [Overview](#overview)
+- [Installation](#installation)
+- [Usage](#usage)
+- [License](#license)
+
+## Overview
+LanceDB-Haystack is an embedded [LanceDB](https://lancedb.github.io/lancedb/) backed Document Store for [Haystack 2.X](https://github.com/deepset-ai/haystack/).
+
+## Installation
+
+The current simplest way to get LanceDB-Haystack is to install from GitHub via pip:
+
+```shell
+pip install lancedb-haystack
+```
+
+## Usage
+
+```python
+import pyarrow as pa
+from lancedb_haystack import LanceDBDocumentStore
+from lancedb_haystack import LanceDBEmbeddingRetriever, LanceDBFTSRetriever
+
+# Declare the metadata fields schema, this lets us filter using it.
+# See: https://arrow.apache.org/docs/python/api/datatypes.html
+metadata_schema = pa.struct([
+  ('title', pa.string()),    
+  ('publication_date', pa.timestamp('s')),
+  ('page_number', pa.int32()),
+  ('topics', pa.list_(pa.string()))
+])
+
+# Create the DocumentStore
+document_store = LanceDBDocumentStore(
+  database='my_database', 
+  table_name="documents", 
+  metadata_schema=metadata_schema, 
+  embedding_dims=384
+)
+
+# Create an embedding retriever
+embedding_retriever = LanceDBEmbeddingRetriever(document_store)
+
+# Create a Full Text Search retriever
+fts_retriever = LanceDBFTSRetriever(document_store)
+```
+
+See also [`examples/pipeline-usage.ipynb`](https://github.com/alanmeeson/lancedb-haystack/blob/main/examples/pipeline-usage.ipynb) for a full worked example, and the [API Reference](https://lancedb-haystack.readthedocs.io).
+
+### License
+
+[Apache License 2.0](https://github.com/alanmeeson/lancedb-haystack/blob/main/LICENSE)