Make it clearer in the doc how to setup feature flag

[ajubin]

It's not really clear what to provide when configuring the module,

maybe do this instead

UnleashModule.forRoot({
    url: 'https://<path-to-your-unleash-server>/api/client',
    appName: '<name-of-your-app-on-unleash>',
    instanceId: '<pick-a-unique-id-to-identify-this-nest-server-on-unleash>',
    http: {
      headers: {
        Authorization:
          '<your-token-for-the-environment>',
      },
    },
  }),

[MichaelPappas26623]

+1 on this one , please update the README if you have time