Update onSignal Function to Accept Signal Parameter

[rsaryev]

Summary

This update modifies the onSignal function, enabling it to accept a signal parameter. Previously, the function was limited in its capability to handle different signals dynamically. This change introduces the flexibility to handle various signal types, enhancing the function's utility and making it more adaptable to different use cases.

createTerminus(server, {
  signal: SIGNAL,
  onSignal: (signal) => {
    console.log(`on-signal-runs: ${signal}`)
    return Promise.resolve()
  }
})