Additional typeclass instances that are not part of the report

The GHC user guide documents the following typeclass instances that are part of `base` but not the report.
```haskell
instance Functor ((->) r)
instance Monad ((->) r)
instance Functor ((,) a)
instance Functor (Either a)
instance Monad (Either e)
```
We will have to check if this list is exhaustive or not.

Start by comparing the GHC user guide's documented base instances with the corresponding instance sections in the revised report. Verify whether the listed instances are exhaustive, then update the report so all missing instances are represented and the final list matches the source documentation.

Written by the indexing model from the issue text.