docs: list who's integrating excalidraw (#4832)

* docs: list who's integrating excalidraw

* Update README.md

README.md

@@ -32,6 +32,10 @@ Last but not least, we're thankful to these companies for offering their service
 
 [![Vercel](./.github/assets/vercel.svg)](https://vercel.com) [![Sentry](./.github/assets/sentry.svg)](https://sentry.io) [![Crowdin](./.github/assets/crowdin.svg)](https://crowdin.com)
 
+## Who's integrating Excalidraw
+
+[Google Cloud](https://googlecloudcheatsheet.withgoogle.com/architecture) • [Meta](https://meta.com/) • [CodeSandbox](https://codesandbox.io/) • [Obsidian Excalidraw](https://github.com/zsviczian/obsidian-excalidraw-plugin) • [Replit](https://replit.com/) • [Slite](https://slite.com/) • [Notion](https://notion.so/) • [HackerRank](https://www.hackerrank.com/) •
+
 ## Documentation
 
 ### Shortcuts