Improved partial content selection

Is your feature request related to a problem? Please describe.

https://asdf-vm.com has the same instructions for ZSH and FISH with Git, regardless of OS. Since there are issues embedding multiple files (or the same file multiple times), we cannot use Docsify embeds to solve this problem by composing embedded sections. The -- Docsify Select Default -- doesn't suffice as we only want to render the values for some selections and have the default for others.

Describe the solution you'd like

Interpret * in the menu options as any, ignoring the option from that select when computing which value to render.

## --*,something,else

Issues:

• how do we alert people to multiple sections conflicting? Should we just render both?

Describe alternatives you've considered

Additional context

Start by tracing the plugin's existing select-menu parsing and content-rendering behavior with the issue's ## --*,something,else example. The change is done when * excludes that selection while matching the other values, and the behavior for conflicting sections is explicitly defined and covered by tests.