Packaging with PyPI

[redruin1]

Since it's written in Python already, it might be rather convenient to make this project installable via pip:

> pip install factorio-mod-downloader

While probably not more convenient than downloading the executable for regular users, this would allow for stuff like CI integrations to be a breeze:

on: [release]
jobs:
  run:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
    steps:
    ...
    - name: Install Python
      uses: actions/setup-python@v5
      with:
        python-version: '3.13'
    - name: Install `factorio-mod-downloader`
      run: pip install factorio-mod-downloader
    - name: Download Factorio mods
      run: factorio-mod-downloader --headless --file "./modpack-url-list.txt" --destination="./some/folder"
    ...
    # Now you have mods locally installed in `some/folder` that you can run tests against automatically!