Make Tails Installer point to the offline website when running inside Tails
Originally created by @anonym on #15234 (Redmine)
I.e. we make it conditional so non-Tails users still get the online link, and Tails users can access the docs even when offline.
- Related to #14962 (closed)
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information