Update CONTRIBUTING.md (#477)

Author: philschmid

CONTRIBUTING.md

@@ -35,6 +35,44 @@ Adding a new guide often involves lots of detailed reviews and we want to make s
 When you're ready, start by using the [notebook
 template](./quickstarts/Template.ipynb) and following the guidance within.
 
+Before submitting your notebook, it's recommended to run linting and formatting tools locally to ensure consistency and adherence to style guidelines.
+
+1. Install Dependencies:
+
+First, install the necessary packages using pip:
+
+```bash
+pip install -U tensorflow-docs
+```
+
+2. Format the Notebook:
+
+Use the nbfmt tool from tensorflow-docs to automatically format your notebook:
+
+```
+python -m tensorflow_docs.tools.nbfmt path/to/notebook
+```
+
+Replace `path/to/notebook` with the actual path to your notebook file.
+
+3. Lint the Notebook:
+
+Use the nblint tool to check for style and consistency issues:
+
+```
+python -m tensorflow_docs.tools.nblint \
+            --styles=google,tensorflow \
+            --arg=repo:google-gemini/cookbook \
+            --arg=branch:main \
+            --exclude_lint=tensorflow::button_download \
+            --exclude_lint=tensorflow::button_website \
+            --arg=base_url:https://ai.google.dev/ \
+            --exclude_lint=tensorflow::button_github \
+            path/to/notebook
+```
+
+Replace `path/to/notebook` with the actual path to your notebook file.
+
 ## Things we consider
 
 When accepting a new guide, we want to balance a few aspects.