Revamp the F.A.Q. page

[vy]

As agreed in the site structure document, revamp faq.adoc with following goals in mind:

• Rework the existing content (formatting, typos, coherence, etc.)
• Replace images with the ones generated using Antora extensions (This will enable developers to update images by changing a couple of lines of code instead of needing to open images in an editor, keeping separate JPG and XCF files, etc.)
• Enrich content with links to the relevant parts of the website whenever possible
• Target 2.x, port to main