docs: adds ecosystem docs for UnstructuredLoader (#653)

* added stay tuned to the end

* linting, linting, linting

* more linting

* update import statement

Author: MthwRobinson

docs/docs/ecosystem/unstructured.md

@@ -0,0 +1,37 @@
+# Unstructured
+
+This page covers how to use [Unstructured](https://unstructured.io) within LangChain.
+
+## What is Unstructured?
+
+Unstructured is an [open source](https://github.com/Unstructured-IO/unstructured) Python package
+for extracting text from raw documents for use in machine learning applications. Currently,
+Unstructured supports partitioning Word documents (in `.doc` or `.docx` format),
+PowerPoints (in `.ppt` or `.pptx` format), PDFs, HTML files, images,
+emails (in `.eml` or `.msg` format), epubs, markdown, and plain text files.
+`unstructured` is a Python package and cannot be used directly with TS/JS, Unstructured
+also maintains a [REST API](https://github.com/Unstructured-IO/unstructured-api) to support
+pre-processing pipelines written in other programming languages. The endpoint for the
+hosted Unstructured API is `https://api.unstructured.io/general/v0/general`, or you can run
+the service locally using the instructions found
+[here](https://github.com/Unstructured-IO/unstructured-api#dizzy-instructions-for-using-the-docker-image).
+
+## Quick start
+
+You can use Unstructured in`langchainjs` with the following code.
+Replace the filename with the file you would like to process.
+If you are running the container locally, switch the url to
+`https://api.unstructured.io/general/v0/general`.
+
+```typescript
+import { UnstructuredLoader } from "langchain/document_loader";
+
+const loader = new UnstructuredLoader(
+  "https://api.unstructured.io/general/v0/general",
+  "langchain/src/document_loaders/tests/example_data/example.txt"
+);
+const docs = await loader.load();
+```
+
+Stayed tuned for future updates, including functionality equivalent to
+`UnstructuredDirectoryLoader` in `langchain`!.