Print node versions with given manpages

[jasonkarns]

If the desired man pages aren't found, look in other node versions and print the node versions (maybe print the location? -w) that do contain the desired man pages.

Perhaps add all node versions' mandirs to manpath and do man -aw? This would print all found manpages, but wouldn't explicitly list the node versions.

Alternatively, iterate over node versions (skipping aliases) and check for the given man pages.