Update doc to new Tails Installer without splash screen (in Debian)

Feature Branch: doc/14677-no-splash-in-debian

Attachments

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Parent Task: #9005 (closed)

Related issues

• Related to #13301 (closed)
• Related to #15533 (closed)
• Blocked by #14650 (closed)
• Blocks #15411 (closed)

Original created by @sajolida on 14677 (Redmine)