docs: adding lines to docker file (#1633)

docs/docs/cloud/deployment/custom_docker.md

@@ -0,0 +1,19 @@
+# How to customize Dockerfile
+
+Users can add an array of additional lines to add to the Dockerfile following the import from the parent LangGraph image. In order to do this, you simply need to modify your `langgraph.json` file by passing in the commands you want run to the `dockerfile_lines` key. For example, if we wanted to use `Pillow` in our graph you would need to add the following dependencies:
+
+```
+{
+    "dependencies": ["."],
+    "graphs": {
+        "openai_agent": "./openai_agent.py:agent",
+    },
+    "env": "./.env",
+    "dockerfile_lines": [
+        "RUN apt-get update && apt-get install -y libjpeg-dev zlib1g-dev libpng-dev",
+        "RUN pip install Pillow"
+    ]
+}
+```
+
+This would install the system packages required to use Pillow if we were working with `jpeq` or `png` image formats. 

docs/docs/cloud/how-tos/index.md

@@ -7,14 +7,20 @@ hide:
 
 Welcome to the LangGraph Cloud how-to guides! These guides provide practical, step-by-step instructions for accomplishing key tasks in LangGraph Cloud.
 
-## Deployment
+## Setup
 
-LangGraph Cloud gives you best in class observability, testing, and hosting services. Read more about them in these how to guides:
+LangGraph Cloud gives you best in class observability, testing, and hosting services. Learn how to setup your app for deployment to LangGraph Cloud in these how-to guides 
 
 - [How to set up app for deployment (requirements.txt)](../deployment/setup.md)
 - [How to set up app for deployment (pyproject.toml)](../deployment/setup_pyproject.md)
 - [How to set up app for deployment (JavaScript)](../deployment/setup_javascript.md)
+- [How to customize Dockerfile](../deployment/custom_docker.md)
 - [How to test locally](../deployment/test_locally.md)
+
+## Deploy
+
+Learn how to deploy your app to LangGraph Cloud in these how to guides:
+
 - [How to deploy to LangGraph cloud](../deployment/cloud.md)
 
 

docs/mkdocs.yml

@@ -204,6 +204,7 @@ nav:
               - Setup App (pyproject.toml): "cloud/deployment/setup_pyproject.md"
               - Setup App (JavaScript): "cloud/deployment/setup_javascript.md"
               - Rebuild Graph at Runtime: "cloud/deployment/graph_rebuild.md"
+              - Customize Dockerfile: "cloud/deployment/custom_docker.md"
               - Test App Locally: "cloud/deployment/test_locally.md"
           - Deployment:
               - Deploy to Cloud: "cloud/deployment/cloud.md"