Can NOT DrawText ASCII and unicode togther

[mailfcly]

test with xamarin forms, SkiaSharp.Views.Forms, android

                var fontManager = SKFontManager.Default;
                var emojiTypeface = fontManager.MatchCharacter('年');
                paint.Typeface = emojiTypeface;

                canvas.DrawText("123年 月456", 20, 80, paint);

result in Android:

[yinyue200]

I think

The real issue is that Skia does not support character fallbacks. If the typeface does not contain the character, it will print a block.

see #232

I think you should also fix your typos in your issue's title and content