home: create 'modules/home' folder

Consolidating all modules under the same path, to clear out the
top-level directory.

modules/home/vim/autoload/ftplugined.vim

@@ -0,0 +1,6 @@
+" Create the `b:undo_ftplugin` variable if it doesn't exist
+function! ftplugined#check_undo_ft()
+    if !exists("b:undo_ftplugin")
+        let b:undo_ftplugin=''
+    endif
+endfunction