tutorial: minor fixes + move code and images to a separate dir

tutorials/code/blog/article.v

@@ -0,0 +1,17 @@
+module main
+
+struct Article {
+	id    int
+	title string
+	text  string
+}
+
+pub fn (app &App) find_all_articles() []Article {
+	db := app.db
+	articles := db.select from Article
+	return articles
+}
+
+
+
+