As the title says, handles the case where there is no empty line before the argument block, which was causing weird patterns to pop up in other libraries (like transformers).

For instance,

Some description
Args:
    - foo

was being converted to

Args:
Some description
    - foo

This was because the paragraph was not seen as completed (no blank line), and the Args: line was appended as soon as it was seen. After this PR, the example above is converted to

Some description

Args:
    - foo

i.e. an empty line before Args: is added when it is missing.