message: docs(quick-start-guide): add hooks example
  This is a squash merge of typegoose/typegoose#387
diff: @@ -187,3 +187,40 @@ await doc.setSpeciesAndSave("SomeOtherSpecies");
  ```
  Note: pre-6.0 instance functions needed `@instanceMethod`, but this is not needed anymore
  +
  +### Hooks
  +
  +Typegoose also supports hooks, they can be used like this:
  +
  +```ts
  +@pre<KittenClass>('save', function() {
  + this.isKitten = this.age < 1
  +})
  +@post<KittenClass>('save', (kitten) => {
  + console.log(kitten.isKitten ? "We have a kitten here." : "We have a big kitty here.")
  +})
  +class KittenClass {
  + @prop()
  + public name?: string;
  +
  + @prop()
  + public species?: string;
  +
  + @prop()
  + public age?: number
  +
  + @prop({ default: false })
  + public isKitten?: boolean
  +
  + public async setSpeciesAndSave(this: DocumentType<KittenClass>, species: string) {
  + this.species = species;
  + return await this.save();
  + }
  +}
  +```
  +
  +For detailed explanation of Hooks, please see [Hooks](api/decorators/hooks.md).
  +
  +Note:
  +- Do not use Arrow Functions, because it will break the binding of `this`
  +- For ESLint users: Make sure that rule `eslint-no-use-before-defining` is disabled, otherwise you might get ESLint errors / warnings
  