Update TextEdit docs - explaining 'override_selected_font_color' role

(cherry picked from commit 6a0e6c285202216847ad2b25d5068f4a9031459f)

doc/classes/TextEdit.xml

@@ -433,6 +433,7 @@
 		</member>
 		<member name="mouse_default_cursor_shape" type="int" setter="set_default_cursor_shape" getter="get_default_cursor_shape" override="true" enum="Control.CursorShape" default="1" />
 		<member name="override_selected_font_color" type="bool" setter="set_override_selected_font_color" getter="is_overriding_selected_font_color" default="false">
+			If [code]true[/code], custom [code]font_color_selected[/code] will be used for selected text.
 		</member>
 		<member name="readonly" type="bool" setter="set_readonly" getter="is_readonly" default="false">
 			If [code]true[/code], read-only mode is enabled. Existing text cannot be modified and new text cannot be added.
@@ -605,6 +606,7 @@
 		<theme_item name="font_color_readonly" type="Color" default="Color( 0.88, 0.88, 0.88, 0.5 )">
 		</theme_item>
 		<theme_item name="font_color_selected" type="Color" default="Color( 0, 0, 0, 1 )">
+			Sets the [Color] of the selected text. [member override_selected_font_color] has to be enabled.
 		</theme_item>
 		<theme_item name="function_color" type="Color" default="Color( 0.4, 0.64, 0.81, 1 )">
 		</theme_item>