fixes a typo in backup dir

.vimrc

@@ -216,4 +216,4 @@ let g:vdebug_options= {
  \ }
 
 "let g:autosave_backup = '~/.local/share/vim-data/backup-plugin'
-let g:autosave_backup = "$XDG_DATA_HOME/vim-data/backup_plugin"
+let g:autosave_backup = "$XDG_DATA_HOME/vim-data/backup-plugin"