Embedding models in plugin directory, refs #207

docs/plugins/directory.md

@@ -24,6 +24,12 @@ These plugins can be used to interact with remotely hosted models via their API:
 
 If an API model host provides an OpenAI-compatible API you can also [configure LLM to talk to it](https://llm.datasette.io/en/stable/other-models.html#openai-compatible-models) without needing an extra plugin.
 
+## Embedding models
+
+{ref}`Embedding models <embeddings>` are models that can be used to generate and store embedding vectors for text.
+
+- **[llm-sentence-transformers](https://github.com/simonw/llm-sentence-transformers)** adds support for embeddings using the [sentence-transformers](https://www.sbert.net/) library, which provides access to [a wide range](https://www.sbert.net/docs/pretrained_models.html) of embedding models.
+
 ## Just for fun
 
 - **[llm-markov](https://github.com/simonw/llm-markov)** adds a simple model that generates output using a [Markov chain](https://en.wikipedia.org/wiki/Markov_chain). This example is used in the tutorial [Writing a plugin to support a new model](https://llm.datasette.io/en/latest/plugins/tutorial-model-plugin.html).