update snapshot_event_handler readme

Author: rushilpatel0

codegen-examples/examples/snapshot_event_handler/README.md

@@ -0,0 +1,54 @@
+# Event Handler with codebase snapshotting
+
+This project is designed to using Modal snapshotting to provide parsed codebase instances with minimal latency, make it more manageable to write event based handlers. 
+
+Follow the instructions below to set up and deploy the application.
+
+## Prerequisites
+
+Before you begin, ensure you have the following installed and configured:
+
+1. **uv**: A tool for managing virtual environments and syncing dependencies.
+2. **Modal**: Ensure you have Modal configured on your system.
+
+## Setup Instructions
+
+1. **Create a Virtual Environment**
+
+   Use `uv` to create a virtual environment with Python 3.13:
+
+   ```bash
+   uv venv --python 3.13
+
+   source ./venv/bin/activate
+   ```
+
+2. **Sync Dependencies**
+
+   Sync the project dependencies using `uv`:
+
+   ```bash
+   uv sync
+   ```
+
+3. **Deploy to Modal**
+
+   Deploy the application to Modal by running:
+
+   ```bash
+   uv run modal deploy event_handlers.py
+   ```
+
+   This command will deploy the Modal app and provide a web URL for your webhook sync.
+
+## Project Structure
+
+- `event_handlers.py`: Contains the main logic for handling events.
+- `pr_tasks.py`: Additional tasks related to pull requests.
+- `.env.template` and `.env`: Environment variable templates and configurations.
+- `pyproject.toml`: Project configuration and dependencies.
+
+
+## Integration
+
+Once deployed, you can use the deployed web_url as the webhook endpoint for your slack, linear, or github webhooks.