I was just bitten by the undocumented feature that `texi2any` generates a `@detailmenu` block if it auto-generates menus, and the top-level menu of a document is not present.
Please make this controllable. For example, an empty
```
@detailmenu
@end detailmenu
```
block at the top-level could indicate that a `@detailmenu` block
should be auto-generated.
Another possibility would be a new command, say, `@nodetailmenu`, to
suppress the generation of a `@detailmenu` block.
Werner
