Replace the screenshot at README.md by a screenshot of newest interface

[vitormattos]

Is your feature request related to a problem? Please describe.

No response

Describe the solution you'd like

Now we have a screenshot at README.md and we need to update this to a newest version of same screen with a good appeal, maybe with a text at the DPF file promoting the LibreSign app.

Describe alternatives you've considered

Maybe replacing this:

https://raw.githubusercontent.com/LibreSign/libresign/9dfd70ecb782300615e2c3aa95edcd52b756ea1f/img/LibreSign.png

By this:

https://raw.githubusercontent.com/LibreSign/libresign/60cfcf71fbb730ef587fc14ff1cc330ee80324a1/img/screenshot/request-signature.png

could be a good idea and also will remove a bit the app size removing an image.

Additional context

No response

[abhilov23]

I would like to work on this.

[vitormattos]

@abhilov23 go ahead!

[vitormattos]

Only by a research purpose: where did you found the LibreSign project?

[vitormattos]

Started to be implemented here #5105 but I think unfortunately the developer gave up on moving forward.