func Edit(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
id := vars["id"]
post_title := vars["title"]
p := categories.GetSingleCategory(id, post_title)
categories.RenderTemplate(w, "edit-category", p)
}
func Index(w http.ResponseWriter, r *http.Request) {
p := categories.GetCategories()
categories.RenderTemplate(w, "categories", p)
}
func New(w http.ResponseWriter, r *http.Request) {
collection := new(categories.Data)
p := collection
categories.RenderTemplate(w, "new-category", p)
}