Support custom destination folder

[dantehemerson]

I want to set as destination folder the current working folder. https://github.com/swinton/screenshot-website/blob/8df7c0fd47799a18a322d2bc78d3918602602d26/index.js#L17

[spier]

Just adding that I would also use a feature to set a custom destination folder.

Right now I have a step in my workflow right after screenshote-website runs, that will copy the generated screenshot to where I want it to be like this:

    - name: Screenshot Markmap Website
      id: screenshot-generator
      uses: swinton/screenshot-website@main
      with:
        <<removed as not helpful for example>>
    - name: Copy Screenshot
      run: cp ${{ steps.screenshot-generator.outputs.path }} .

[aboveje]

+1 for this