Added glyph variants

docs/sfn_format.md

@@ -39,9 +39,7 @@ SSFN can store everything that a TrueType or OpenType font can, except for:
 As for character encoding, SSFN exclusively uses UNICODE (ISO-10464) by design. For
 ligatures, I suggest to use the proper UNICODE code point for the ligature (which can
 be a combined glyph), or a sequence of more code points where only the last glyph has
-an advance. As for glyph alternatives, SSFN always renders the same glyph for the same
-character. So if you want to have different glyphs for a character, you have to use a
-different font.
+an advance.
 
 The format was designed with small file size and efficient info access in mind. As
 such the format specification has many IF-x-THEN conditions, because it uses