Add Zestful (#980)

README.md

@@ -369,6 +369,7 @@ API | Description | Auth | HTTPS | CORS |
 | [TheMealDB](https://www.themealdb.com/api.php) | Meal Recipes | `apiKey` | Yes | Yes |
 | [What's on the menu?](http://nypl.github.io/menus-api/) | NYPL human-transcribed historical menu collection | `apiKey` | No | Unknown |
 | [WhiskyHunter](https://whiskyhunter.net/api/) | Past online whisky auctions statistical data | No | Yes | Unknown |
+| [Zestful](https://zestfuldata.com/) | Parse recipe ingredients | `apiKey` | Yes | Yes |
 | [Zomato](https://developers.zomato.com/api) | Discover restaurants | `apiKey` | Yes | Unknown |
 
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