Allow up to two empty lines between top-level declarations

[i-am-the-slime]

This was raised by @wclr on Discord, and I don't see why we wouldn't support this.

[wclr]

Actually, as I love and use in my code this vertically sparse style I have a number of more concrete rules for it, that I found to be very nice. (These rules are mostly derived from the style I've seen Elm's creator Evan Czaplicki uses, as well in his Haskell code - and it definitely helps to make his code much more clean and readable).

Top Level Rules:

• Two (2) empty lines between top-level blocks (declarations, functions).

• Two (2) empty lines between a module declaration and the first import statement.

• One (1) empty line between open and qualified imports (following compiler's import formatting rules).

• Single line top-level declarations can be squashed together without (0) empty lines between.

foregin import intToStr :: Int -> String
foregin import strToInt :: String -> Int

• Three (3) empty lines before orphan comments (which are often used to denote a new code section). Orphan comments are comments that are not followed by a line of the code, but an empty line.