Formatting only GADT with "indent 2" instead of "same_line"

SH formats my GADTs instead of this:
```hs
data Foo a where
SomeA :: String -> Foo ()
SomeB :: Bool -> Foo String
SomeC :: String -> Foo ()
```
like this:

```hs
data Foo a where SomeA :: String -> Foo ()
SomeB :: Bool -> Foo String
SomeC :: String -> Foo ()
```

This is probably due to this setting
```yaml
- records:
equals: "same_line"
# instead of
# equals: "indent 2"
```

Is there some way to distinguish between GADTs and normal records so I can keep the "same_line" option but format GADT with an indent?