Fore-/Backsights old setting doesn't work

[tarquinwj]

Menu - Input mode - Fore-/Backsights

The documentation des not say exactly how this should work, and needs to say that a single splay is required in each direction.

Settings - Automatic backsight promotion used to do the same thing, but is no longer needed (and does not do anything). It should be removed.

Android 11 SexyTopo 1.6.1