Make README more welcoming for first-time contributors

Author: Nitishak06

README.md

@@ -35,3 +35,6 @@ This project is dual-licensed under:
 
 * **Creative Commons Attribution 4.0** - for documentation and content in the assets, content, and data folders (see [LICENSE](LICENSE))
 * **MIT License** - for code (see [LICENSE-CODE](LICENSE-CODE))
+
+* First-time contributors are welcome, and small documentation improvements are a great way to get started.
+