Update wording to use DynamicFont theme overrides in Your first 2D game (#5617)

getting_started/first_2d_game/06.heads_up_display.rst

@@ -36,11 +36,11 @@ Inspector. The default font for ``Control`` nodes is small and doesn't scale
 well. There is a font file included in the game assets called
 "Xolonium-Regular.ttf". To use this font, do the following:
 
-1. Under "Custom Fonts", choose "New Font"
+1. Under "Theme Overrides/Fonts/Font", choose "New DynamicFont"
 
 .. image:: img/custom_font1.png
 
-2. Click on the "Font" you added, and under "Font/Data/0",
+2. Click on the "DynamicFont" you added, and under "Font/Font Data",
    choose "Load" and select the "Xolonium-Regular.ttf" file.
 
 .. image:: img/custom_font2.png
@@ -48,7 +48,7 @@ well. There is a font file included in the game assets called
 Once you've done this on the ``ScoreLabel``, you can click the down arrow next
 to the Font property and choose "Copy", then "Paste" it in the same place
 on the other two Control nodes.
-Set "Custom Font Size" property of the ``ScoreLabel``. A setting of ``64`` works well.
+Set "Size" property of the "DynamicFont" under "Settings/Size". A setting of ``64`` works well.
 
 .. image:: img/custom_font3.png