fix tutorial

[liguoqinjim]

fix tutorial-3 two typo in branch relaase/v1.2.2.

And The question why I only change one picture is that when I did the tutorial.

{
  authors_and_ratings(func: ge(rating, 4.0)) {
    author_name
    rating

    published @filter(lt(dislikes, 10)) {
      title
      likes
      dislikes
      tagged {
        tag_name
      }
    }
  }
}

I found only the rating predicate need a index.I didn't add index for dislikes.The query still work.

I have test for several times,and I also start a new docker container to run the test.The result is same.So whether the dislike predicate need a index when use filter query?

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[liguoqinjim]

@martinmr Ok.I understood.And I revert the change to image.😀

[MichelDiz]

Dgraph Documentation Has Moved! Please open a new PR at https://github.com/dgraph-io/dgraph-docs