Update README.md

[Poussinou]

Hi,

This small PR adds a button to get your app on F-Droid. You can later add a button for Google Play the same way :
[<img src="https://play.google.com/intl/en_us/badges/images/generic/en-play-badge.png" alt="Get it on Google Play" height="80">]()

It also adds a link to get the latest APK from the Releases Section.

You can now eventually add the fdroid and/or f-droid tags that will appear on the right side of the repo.

[wba2hi]

Hi @Poussinou

Thanks for your contribution. It's much appreciated.

Your changes look fine. However, please note, that before we are able to merge your PR you need to sign of the Eclipse Contributor Agreement (ECA). You can find a guide here: https://adoptium.net/en-GB/docs/eca-sign-off/

Also note, that we are using Conventional Commits with Semantic Versioning, please adapt your commit message accordingly, e.g.: "docs: Add F-Droid Badge to README.md" - check our CONTRIBUTING.md for more info

Feel free to reach out to us, when you have any questions or help is needed

[Poussinou]

Sorry, I'll never sign an agreement like this one, it's against my principles. No offense intended :)

You can basically copy-paste the button !