Update FAQ

[Alphrag]

Add in the FAQ some questions concerning:

• warnings when executing the app the first time on MacOS and Windows;
• status of code signing and certificates, with the value of the publisher name;
• the different assets available in the releases.

Also fix typo in Contributing.md when cloning repo.

[Alphrag]

Do we need to modify the value of the projectName from website to ferdium-website in the .all-contributorsrc file as well?