Added a solution for another installation case

README.md

@@ -34,7 +34,12 @@ This is how to create the contract bytecode to output _Hello, World!_ in Huff.
     yarn global add huffc
     ```
 
-**Note:** You may need to add yarn to your system's path to access globally installed packages. See [the yarn docs on global](https://classic.yarnpkg.com/en/docs/cli/global) for more details.
+**Note:** You may need to add yarn to your system's path to access globally installed packages. See [the yarn docs on global](https://classic.yarnpkg.com/en/docs/cli/global) for more details. 
+
+Also try with sudo as there may still be an issue with Yarn incorrectly using the Node.js installation directory as the executable directory, which is not writable by normal users:
+
+       sudo yarn global add huffc
+
 
 ## Hello World