message: docs(quick-start-guide): remove arrow function in hooks example
  Since one of the notes says:
  > - Do not use Arrow Functions, because it will break the binding of `this`
  The hooks usage example shouldn't expose arrow functions as a valid way to use it
diff: @@ -237,7 +237,7 @@ Typegoose also supports hooks. They can be used like this:
  @pre<KittenClass>('save', function() {
  this.isKitten = this.age < 1
  })
  -@post<KittenClass>('save', (kitten) => {
  +@post<KittenClass>('save', function(kitten) {
  console.log(kitten.isKitten ? 'We have a kitten here.' : 'We have a big kitty here.')
  })
  class KittenClass {
  