Docs fix (#1517)

* Changes in editing style for changelog and FAQ. Changing also the answer to the installation question in the FAQ.
* Moving the footer.html page inside the doc folder.
* added consistent line breaking between versions
* removed leftover file
* Update doc/faq_tips/faq.md

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Co-authored-by: Sein Coray <[email protected]>
Co-authored-by: Copilot <[email protected]>

Author: 3 people