global options example: pass arguments to sub-subcommands too

[arve0]

Problem

Was hard to understand why sub-subcommand did not get option, even though --help shows the option. I read the example, others will probably too. Expand it to also add options to sub-subcommands.

See issue #1753.

Solution

Added sub-subcommand to global-options example.

[shadowspawn]

Thanks for the suggestion, but I don't want repeated ("inherited") options in nested subcommands in this example file. That is a complex pattern with some drawbacks.

I wrote this example so that options are only added in "leaf" commands, so options are not repeated at different levels of the hierarchy. To keep the code simple I limited the subcommands to just one level deep.

Note the name of the Command subclass (MyRootCommand), and also the comment on line 6:

// The code in this example assumes there is just one level of subcommands.