PlayerDinger - Player join sound effect

Added a config, permissions, metrics.

config now allows you to define a sound effect, pitch and volume. -suggested by xclucky

permissions for causing a ding, and receiving a ding. -suggested by xclucky

new reload command.
commands:
  playerdingerdebug:
    description: Toggles your debugging status for this plugin.
    usage: /playerdingerdebug sound pitch volume
    permission: playerdinger.debugcommand
  playerdingerreload:
    description: reloads the config for playerdinger.
    usage: /playerdingerreload
    permission: playerdinger.reload

permissions:
  playerdinger.*:
    description: Gives access to all playerdinger commands
    children:
      playerdinger.debugcommand true
      playerdinger.ding.cause true
      playerdinger.ding.receive true
      playerdinger.reload true
  playerdinger.debugcommand
    description: Allows usage of playerdingerdebug
    default: OP
  playerdinger.ding.receive
    description: Allows you to receive player dings
    default: true
  playerdinger.ding.cause
    description: players with this permissions will cause a ding on join
    default: true
  playerdinger.reload
    description: allows player to reload the config
    default: OP