Add Elixr version

README

@@ -106,3 +106,4 @@ mndecode.c	Sample program - decode data from stdin to stdout
 JavaScript: <https://github.com/mbrubeck/mnemonic.js>
 Go:         <https://bitbucket.org/dchapes/mnemonicode>
 Python:     <https://github.com/bwhmather/python-mnemonicode>
+Elixr:      <https://github.com/mwmiller/mnemonex>