Add set of strings for tags.

src/main/lombok/org/leumasjaffe/recipe/model/RecipeCard.java

@@ -1,8 +1,10 @@
 package org.leumasjaffe.recipe.model;
 
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 import java.util.stream.Stream;
 
 import javax.swing.ImageIcon;
@@ -17,6 +19,7 @@ public class RecipeCard extends Observable.Instance implements CompoundRecipeCom
 	String title = "";
 	String description = "";
 	int servings = 1;
+	Set<String> tags = new HashSet<>();
 	// TODO: Nutrition information
 	Optional<ImageIcon> photo = Optional.empty(); // TODO JSONIZATION	
 	List<Element> elements = new ArrayList<>();