feat(freetype): add colored glyphs support (#6686)

Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>

docs/libs/freetype.rst

@@ -4,7 +4,7 @@
 FreeType support
 ================
 
-Interface to FreeType library to generate font bitmaps run time.
+Interface to FreeType library to generate font bitmap at run time.
 
 Detailed introduction: https://www.freetype.org
 
@@ -89,14 +89,18 @@ software, and can be set with reference to the following values:
 They can be combined.eg:
 :cpp:expr:`LV_FREETYPE_FONT_STYLE_BOLD | LV_FREETYPE_FONT_STYLE_ITALIC`.
 
+The FreeType extension also supports colored bitmap glyphs such as emojis. Note
+that only bitmaps are supported at this time. Colored vector graphics cannot be
+rendered. An example on how to draw a colored bitmap glyph is shown below.
+
 Use the :cpp:func:`lv_freetype_font_create` function to create a font. To
 delete a font, use :cpp:func:`lv_freetype_font_delete`. For more detailed usage,
 please refer to example code.
 
 .. _freetype_example:
 
-Example
--------
+Examples
+--------
 
 .. include:: ../examples/libs/freetype/index.rst
 

docs/overview/font.rst

@@ -428,12 +428,9 @@ LVGL's font interface is designed to be very flexible but, even so, you
 can add your own font engine in place of LVGL's internal one. For
 example, you can use `FreeType <https://www.freetype.org/>`__ to
 real-time render glyphs from TTF fonts or use an external flash to store
-the font's bitmap and read them when the library needs them.
+the font's bitmap and read them when the library needs them. FreeType can be used in LVGL as described in :ref:`Freetype <freetype>`.
 
-A ready to use FreeType can be found in
-`lv_freetype <https://github.com/lvgl/lv_lib_freetype>`__ repository.
-
-To do this, a custom :cpp:type:`lv_font_t` variable needs to be created:
+To add a new font engine, a custom :cpp:type:`lv_font_t` variable needs to be created:
 
 .. code:: c