Update contributing guide for publishing

Signed-off-by: Prithvi Kannan <[email protected]>

CONTRIBUTING.md

@@ -1,10 +1,34 @@
-Setting up dev environment
+# Contributor's Guide
+
+## Setting up dev environment
 
 Create a conda environement and install dev requirements
 
-```
+```sh
 conda create --name databricks-ai-dev-env python=3.10
 conda activate databricks-ai-dev-env
 pip install -e ".[dev]"
 pip install -r requirements/lint-requirements.txt
 ```
+
+## Publishing to PyPI
+
+Note: this section is for maitainers only.
+
+We recommend first uploading to test-PyPI
+
+### Publishing core package
+
+
+```sh
+python3 -m build --wheel
+twine upload dist/*
+```
+
+### Publishing integration packages
+
+```sh
+cd integrations/langchain
+python3 -m build --wheel
+twine upload dist/*
+```