Instructions link does not work

```txt
See [instructions](bit.ly/grpc-java-lab-doc)
```
which redirects to 

```txt
https://github.com/saturnism/grpc-java-chatroom-workshop/blob/master/bit.ly/grpc-java-lab-doc
```

should be
```txt
See [instructions](http://bit.ly/grpc-java-lab-doc)
```