nvim: init: Disable Rust ftplugin mappings

See
920ef1fd71.

nvim/.config/nvim/init.lua

@@ -103,6 +103,9 @@ vim.g.tmux_navigator_no_mappings    = 1
 -- Write the current buffer, but only if changed before navigating from Vim to tmux pane
 vim.g.tmux_navigator_save_on_switch = 1
 
+-- Disable ]]/[[ style bindings
+vim.g.no_rust_maps = 1
+
 -- We do this to prevent the loading of the system fzf.vim plugin. This is
 -- present at least on Arch/Manjaro
 vim.cmd.set{ args = { 'rtp-=/usr/share/vim/vimfiles' } }