docs: added badge and link to build package workflow (#18795)

Author: operagxsasha

README.md

@@ -1,6 +1,7 @@
 # 🗂️ LlamaIndex 🦙
 
 [![PyPI - Downloads](https://img.shields.io/pypi/dm/llama-index)](https://pypi.org/project/llama-index/)
+[![Build](https://github.com/run-llama/llama_index/actions/workflows/build_package.yml/badge.svg)](https://github.com/run-llama/llama_index/actions/workflows/build_package.yml)
 [![GitHub contributors](https://img.shields.io/github/contributors/jerryjliu/llama_index)](https://github.com/jerryjliu/llama_index/graphs/contributors)
 [![Discord](https://img.shields.io/discord/1059199217496772688)](https://discord.gg/dGcwcsnxhU)
 [![Twitter](https://img.shields.io/twitter/follow/llama_index)](https://x.com/llama_index)