video: indicate code page of bitmap fonts

Add comments clarifying that the bitmap fonts support code page 437.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/include/video_font_4x6.h b/include/video_font_4x6.h
index 6aeed09..64c5ed2 100644
--- a/include/video_font_4x6.h
+++ b/include/video_font_4x6.h
@@ -1,5 +1,5 @@
-/* Hand composed "Minuscule" 4x6 font, with binary data generated using
- * Perl stub.
+/* Hand composed "Minuscule" 4x6 font for code page 437, with binary data
+ * generated using Perl stub.
  *
  * Use 'perl -x mini_4x6.c < mini_4x6.c > new_version.c' to regenerate
  * binary data.