docs(font) fix example to match v8
Closes Thanks for bringing this to our attention
In LVGL fonts are collections of bitmaps and other information required to render images of individual letters (glyph).
A font is stored in a `lv_font_t` variable and can be set in a style's *text_font* field. For example:
```c
-lv_style_set_text_font(&my_style, LV_STATE_DEFAULT, &lv_font_montserrat_28); /*Set a larger font*/
+lv_style_set_text_font(&my_style, &lv_font_montserrat_28); /*Set a larger font*/
```
Fonts have a **bpp (bits per pixel)** property. It shows how many bits are used to describe a pixel in a font. The value stored for a pixel determines the pixel's opacity.
