Update README.md

Author: unbalancedparentheses

README.md

@@ -33,7 +33,7 @@ Dream of becoming an Ethereum core developer? Eager to shape the protocol that w
 
   ```shell
   git clone [REPO_URL]
-  cd lambda-ethereum-consensus
+  cd lambda_ethereum_consensus
   ```
 
 - **Setup**: Once you've cloned the repository, follow the steps in the [Installing and running](#installing-and-running) section to set up your environment.