add info on contributing to docs

Author: humford

README.md

@@ -1,3 +1,31 @@
 # VAPI API Documentation
 
-This repository contains the source files for the documentation found at [docs.vapi.ai](https://docs.vapi.ai/). You can suggest edits by making a pull request.
+This repository contains the source files for the documentation found at [docs.vapi.ai](https://docs.vapi.ai/). 
+
+## How can I contribute to these docs?
+
+You can suggest edits by making a pull request.
+
+## How to update documentation?
+
+### Local Development server
+
+To run a local development server with hot-reloading you can run the following command
+
+```sh
+fern docs dev
+```
+
+#### Hosted URL
+
+To update your documentation on a hosted URL, run
+```
+# npm install -g fern-api
+fern generate --docs
+```
+To preview your documentation, run
+```
+# npm install -g fern-api
+fern generate --docs --preview
+```
+The repository contains GitHub workflows that will automatically run these commands for you. For example, when you make a PR a preview link will be auto-generated and when you merge to main the docs site will update.