Update index.md (MystenLabs#868)

Fix error in bullet point

doc/src/contribute/index.md

@@ -26,6 +26,6 @@ To submit your pull request:
 
 * Learn [about Mysten Labs](https://mystenlabs.com/) the company on our public site.
 * Read the [Sui Smart Contract Platform](../../paper/sui.pdf) white paper.
-* * Implementing [logging](observability.md) in Sui to observe the behavior of your development.
+* Implementing [logging](observability.md) in Sui to observe the behavior of your development.
 * Find related [research papers](research-papers.md).
 * See and adhere to our [code of conduct](code-of-conduct.md).