bug: when document start have comments before, formatter moves it on top of the file.

[vveliev]

When yaml includes comments before document start formatters moves it on the top.

Here is the example yaml file:

# -*- coding: utf-8 -*-
# vim: ft=yaml
# yamllint disable rule:truthy
---
name: ci-pipeline

on:
  pull_request:
  push:
    branches: [main]

when using formatter with this options I'm not expecting any changes
-formatter include_document_start=true,retain_line_breaks_single=true

instead I'm getting this:

---
# -*- coding: utf-8 -*-
# vim: ft=yaml
# yamllint disable rule:truthy
name: ci-pipeline

on:
  pull_request:
  push:
    branches: [main]