Add myself to the Advent shcedule

Author: jnthn

misc/perl6advent-2017/schedule

@@ -8,7 +8,7 @@ Please add your topic and name after each day that you plan to take.
  6:
  7:
  8: [NEED THIS SPOT? TAKE IT!] moritz: A chapter from "Parsing with Perl 6 Regexes and Grammars"
- 9:
+ 9: jnthn: HTTP and WebSockets with Cro
 10: bduggan: "Measurement with Rats"
 11:
 12: moritz: "Perl 6 Books"