add newline feature to the text node, add about window with credits, add about menu with submenus

src/font.h

@@ -16,6 +16,7 @@ public:
     const int h = 512;
     const int num_chars = 96;
     const int start_char = 32;
+    int size = 0;
     stbtt_fontinfo font;
     Texture2D font_tex;
     std::vector<stbtt_bakedchar> chars;