Scroll one screenful forward in Info, considering all nodes as one sequence.
Once you scroll far enough in a node that its menu appears on the screen
but after point, the next scroll moves into its first subnode, unless
`Info-scroll-prefer-subnodes' is nil.
When you scroll past the end of a node, that goes to the next node if
`Info-scroll-prefer-subnodes' is non-nil and to the first subnode otherwise;
if this node has no successor, it moves to the parent node's successor,
and so on. If `Info-scroll-prefer-subnodes' is non-nil and point is inside
the menu of a node, it moves to subnode indicated by the following menu
item. (That case won't normally result from this command, but can happen in other ways.)