nixpkgs/neovim: re-add signcolumn to avoid layout shift

.config/nixpkgs/neovim/settings.lua

@@ -28,6 +28,9 @@ vim.o.breakindentopt = 'shift:2,sbr'
 -- show whitespace
 vim.o.list = true
 
+-- always show sign column to avoid layout shift when staging
+vim.o.signcolumn = 'yes'
+
 -- make a new copy of the file for backup
 -- setting to no or auto messes with filewatchers
 vim.o.backupcopy = 'yes'