Document workaround for Tails freezing with NVIDIA GTX 1080 when HTC Vive headset is connected to HDMI

Originally created by @intrigeri on #14697 (Redmine)

• Reference: #11831 (comment 54972)
• Problem: Tails freezes (not sure at which time exactly)
• Workaround: unplug that headset before starting Tails
• Affected hardware:
  • at least NVIDIA GTX 1080, but most likely all Pascal GPUs
  • at least HTC Vive headset, and perhaps more HDMI devices

More generally, various reports tell us that a number of problems with nouveau drivers for NVIDIA graphics can be workaround’ed by unplugging non-essential devices connected to the NVIDIA thing (e.g. 2nd display, sound outputs etc.) or by plugging displays on a different port.

It might be worth pointing to https://nouveau.freedesktop.org/wiki/CodeNames/ (so users can identify their hardware) and https://nouveau.freedesktop.org/wiki/FeatureMatrix/ (so that users can tell whether the issue they’re experiencing is Tails-specific or not).

Related issues

• Related to #11831 (closed)
• Related to #14965 (closed)
• Blocks #14758 (closed)