Add better flashbacks

[Demizo]

Improve home screen flashbacks and fixed entries showing in more than one flashback. Added flashbacks:

• 1 month ago
• 6 months ago
• x years ago, closes #19
• A random day
• A happy day

[Aditya137x]

Love this update. I wanyed an app like Daily You for sooo long and this update maked the app even better. Thanks alot for creating the app @Demizo