Avram::DeleteOperation(T) class doc doesn't document constructors

The class doc for `Avram::DeleteOperation` doesn't document its constructors. It should give:

```
#new(record : T, params : Avram::Paramable)
#new(record : T)
```

Start at the Avram::DeleteOperation class documentation and inspect how its constructors are currently described. Compare the documentation with the two constructor signatures named in the issue, then verify that both overloads are shown in the generated class documentation.

Written by the indexing model from the issue text.