Updated contributing steps for next-server (#5405) (#5518)

contributing.md

@@ -7,7 +7,7 @@ Our Commitment to Open Source can be found [here](https://zeit.co/blog/oss)
 3. Run `npm run bootstrap`, which will link all repositories locally
 4. Run `npm run dev` to build and watch for code changes
 
-### To run tests
+## To run tests
 
 Running all tests:
 
@@ -27,26 +27,30 @@ Running just one test in the `production` test suite:
 yarn testonly --testPathPattern "production" -t "should allow etag header support"
 ```
 
-### Running the integration test apps without running tests
+## Running the integration test apps without running tests
 
 ```
 ./node_modules/.bin/next ./test/integration/basic
 ```
 
-### Testing in your own app
+## Testing in your own app
 
-You only have to link the package once:
+First `next-server` needs to be linked:
 
 ```
-cd packages/next
+cd packages/next-server
+npm link
 ```
 
+Then `next` needs to link to `next-server`, and be linked itself:
+
 ```
+cd packages/next
 npm link
+npm link next-server
 ```
 
-
-Then link the `next` package inside your app:
+And finally, link the `next` package inside your app:
 
 ```
 npm link next