Add verified Series 20 tasks from taskmaster.info

All 10 S20 episodes now have real task data from taskmaster.info
(episode IDs 834-843). 50 verified tasks total.

All 20 series (182 episodes, 949 tasks) now 100% verified from
taskmaster.info episode synopses. No fabricated data remains.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: haileyhuber8