About a slight change to Extra Chapters release

Due to mental health reasons, I'll be withdrawing the releasing of extra chapters for a while, but the regular release schedule will remain the same.

Thanks for the kind consideration, guys.

- New Rewards for Milestones: 30 Power Stones = 01 Extra Chapter

 50 Power Stones = 01 Extra Chapter

 100 Power Stones = 02 Extra Chapters

 150 Power Stones = 02 Extra Chapters

 300 Power Stones = 04 Extra Chapters

* For every 50 Power stones given, from the 300 PS milestone on, there will be 01 extra chapter.