fix(docs/contributing): correct pnpm link command

Author: stainless-app[bot]

CONTRIBUTING.md

@@ -60,7 +60,7 @@ $ yarn link contextual-client
 # With pnpm
 $ pnpm link --global
 $ cd ../my-package
-$ pnpm link -—global contextual-client
+$ pnpm link --global contextual-client
 ```
 
 ## Running tests