Add a rule to disallow extra newlines before a block closes

[tremby]

The following currently produces no warnings or errors:

.container {
  button {

    display: block;

  }

}

I expect warnings for lines 3, 5, and 7, since I don't want those extra blank lines, even though blank lines between blocks should be allowed.

Am I missing an existing rule which will do this? Or perhaps one could be added.

[saltire]

Here's the ESLint equivalent: https://eslint.org/docs/rules/padded-blocks