Add an admin flag to user

backend/templates/recipe_view.html

@@ -5,7 +5,7 @@
 <div class="content" id="recipe-view">
     <h2 class="recipe-title" >{{ recipe.title }}</h2>
 
-    {% if user.is_some() && recipe.user_id == user.as_ref().unwrap().id %}
+    {% if user.is_some() && crate::data::model::can_user_edit_recipe(&user.as_ref().unwrap(), &recipe) %}
         <a class="edit-recipe" href="/recipe/edit/{{ recipe.id }}" >Edit</a>
     {% endif %}