Update unicode.md

Author: isedwards

unicode.md

@@ -1,3 +1,4 @@
-- [Absolute minimum](https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/)
+- [Shapecatcher](http://shapecatcher.com/)
+- [Absolute minimum](https://www.joelonsoftware.com/2003/10/08/the-absolute-minimum-every-software-developer-absolutely-positively-must-know-about-unicode-and-character-sets-no-excuses/) that every software developer should know about unicode.
 - `\u3053` is a unicode character from the unicode character set (`&#x3053` in [HTML](https://software.hixie.ch/utilities/cgi/unicode-decoder/utf8-decoder)).
   [Encoded as UTF-8](https://stackoverflow.com/questions/1229414/unicode-utf-8-utf-16-encoding-in-python): `\xe3\x81\x93`