Module and ppx's breaks the highlight under ppx payload

Hey,

This highlights correct,
```reason
[%styled.div {|
  display: flex;
|}];
```

while this breaks.
```reason
module Compo = [%styled.div {|
  display: flex;
|}];
```

I tried to look into it but seems very vague to understand how all of this works. Happy to work on this thought.