How-to for removing transmission settings to services, update FAQ

• Review here
• Edit here

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• Add how-to on reverting revokal of user data transmission to services ( https://gitlab.hzdr.de/hifis/overall/hifis-technical-documentation/-/issues/52 )
• Makes FAQ clickable
• some minor reformatting/link updates in FAQ

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Closes https://gitlab.hzdr.de/hifis/overall/hifis-technical-documentation/-/issues/52