'(info-stnd)Invoking Info' doesn't mention that '--show-options' requires arguments

[Akbarkhon Variskhanov]

doc/info-stnd.texi#n483

info/info.c#n1109

Something like:

'--show-options PROGRAM'

'--usage PROGRAM'

'-O PROGRAM'

is needed to make it clearer. I thought info --usage would display a short summary for info's options like it does in many other GNU programs but info returns 1 on exit instead and outputs this message:

info: No program name given