Remove modstore leftovers. Fix core.show_path_select_dialog documentation (#8572)

This was forgotten in #5852.

doc/menu_lua_api.txt

@@ -89,13 +89,14 @@ core.set_background(type, texturepath,[tile],[minsize])
 core.set_clouds(<true/false>)
 core.set_topleft_text(text)
 core.show_keys_menu()
-core.file_open_dialog(formname,caption)
-^ shows a file open dialog
+core.show_path_select_dialog(formname, caption, is_file_select)
+^ shows a path select dialog
 ^ formname is base name of dialog response returned in fields
 ^     -if dialog was accepted "_accepted"
-^^       will be added to fieldname containing the path
+^        will be added to fieldname containing the path
 ^     -if dialog was canceled "_cancelled"
 ^        will be added to fieldname value is set to formname itself
+^ if `is_file_select` is `true`, a file and not a folder will be selected
 ^ returns nil or selected file/folder
 core.get_screen_info()
 ^ returns {
@@ -240,4 +241,4 @@ Limitations of Async operations
  -No access to global lua variables, don't even try
  -Limited set of available functions
 	e.g. No access to functions modifying menu like core.start,core.close,
-	core.file_open_dialog
+	core.show_path_select_dialog