Update schedule

Took the 12th

Author: MorayJ

misc/perl6advent-2018/schedule

@@ -14,7 +14,7 @@ exists: https://github.com/zoffixznet/perl6-Acme-Advent-Highlighter
  9: hankache: TBA
 10: Nige: TBA
 11: daotoad: Writing Command Line Tools in Perl6
-12:
+12: MorayJ: Parsing present lists with grammars
 13: ramiroencinas: Web server from scratch with Cro and Debian
 14: koto: TBA
 15: tobs: Propositional combinatorics in Perl 6