I absolutely don't how the file "postfixbook/postfixbook.js" has to be
structured. It's not clear to me, even when reading the README.md you proposed.
Maybe something like:
"
{
name: '$plugin_name',
path: 'plugins/$plugin_name'
}
"
But how to continue? I mean, do I have to put this inside an array or an JSON object etc.
How would that look like for multiple plugins like I have?