Showing the 'number' column in terminal buffers is a bit silly because
of 'scrollback'. But it's mostly harmless and technically works as
expected.
The least surprising thing is to leave the user's settings alone. Since
there are tradeoffs in both cases, we choose inertia.
We still disable 'relativenumber' in *terminal-mode* (as opposed to
normal-mode) because it is totally broken: the Nvim cursor (not terminal
cursor) is always on the last line.
A couple lines tripped me up while reading through this document for the first
time. This change aims to reword/rework these areas, so that they are clearer
on the first read.
