[question] how to install CLI plugins?

hi, I wonder how to install plugins for sfdx CLI. I tried something like this in `compile` script:
```
install_sfdx_cli_plugins() {
log "Installing sfdx plugins ..."
sfdx plugins:install @salesforce/plugin-name
}
```

and call it after `install_sfdx_cli`:
```
setup_dirs
log "Starting CLI installation ..."
install_sfdx_cli
install_sfdx_cli_plugins
```

in the output I can see how my plugins are installed, but after, in heroku I do a `sfdx plugins --core` and I can't see my plugins

any idea?