stylish-haskell deletes Haddock export list documentation

Best explained by example.

Given this bit of module export list:
```
-- * Table handles
, TableHandle
, TableConfig (..)
, new
, close
-- ** Resource management
-- $resource-management

-- * Table queries and updates
-- ** Queries
, lookups
, LookupResult (..)
```
stylish-haskell wants to delete these three lines entirely
```
-- ** Resource management
-- $resource-management

```
This is obviously wrong. That section heading and corresponding bit of documentation is important. It must not be deleted.

But also, the trailing blank line there is *necessary* syntax. Without it, haddock will merge the subsequent section in, rather than giving it its own section name "Table queries and updates".

```
$ stylish-haskell --version
stylish-haskell 0.14.5.0
```