Add setter docs for GlfwWindow#renderCode

windowing/glfw/src/main/java/de/staropensource/engine/windowing/glfw/implementation/GlfwWindow.java

@@ -83,6 +83,11 @@ public final class GlfwWindow extends Window {
      *
      * @return rendering code
      * @since v1-alpha8
+     * -- SETTER --
+     * Sets the code to execute in {@link #render()}
+     *
+     * @param renderCode new rendering code
+     * @since v1-alpha8
      */
     @Getter
     @Setter