Alternate files: link if executable found in $PATH

[tralce]

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

No.

Describe the solution you'd like

I would like an additional condition for alternate files: executable/x

Idea being the alternate is only linked if the command listed after ##x. is executable / in $PATH

for example, the file .config/yadm/alt/.bin/proxmox_zfs_commands.sh##x.pvedaemon will only be symlinked to ~/.bin/proxmox_zfs_commands.sh if the command pvedaemon is found.

Describe alternatives you've considered

Well, there really isn't an alternative for this, as it isn't a feature. I've kind of made it work with Classes, OSes, Distros, etc but that does have a high management overhead.

Additional context

I have a fair number of config files and scripts set up as Alternate Files that only need to be present if a certain program is installed.

Thank you for considering this idea!