Lethal Love: a Yandere game

Experience Kei’s True Ending Now!
- Added True Ending for Chapter Two (Kei);
- Added a hint option to the main menu;
- Improved Sanity system: as Kyoko's sanity decreases, the screen's saturation gradually fades to black and white;
- Added text in the chapter selection (rivals) showing the current state of development of each rival;
- Now you don't need to do Sakura's true ending to unlock Kei's chapter;
- Some routines have been updated;
- Corrected various spelling errors.