Feature request - Add a comment to auto-generated files stating the files are auto-generated

[occasional-contributor]

Feature request - Add a comment to auto-generated files stating the files are auto-generated

Just like poetry.lock files, the requirements.txt files generated using this plugin could use a comment at the top stating that the file was auto-generated using poetry vx.y.z and poetry-plugin-export vx.y.z.

Thank you.