Documentation and Services improvements

Added 3 examples to the manual update. One simply adds a static date, one creates date twins, and the last one basically replaces the holiday_in_week_move feature. If I make it into a blueprint, is it a good replacement for the parameter? Can I make it obsolete?
Let me know in the comments of #287
It is a bit more work, but it gives the ultimate flexibility, and there are so many requests for different versions, exceptions, flavors (like if it moves to the weekend, move it somewhere else, etc).

Check out the README for examples.

This is related to the manual_update feature. Check the 4.0.0 release notes.