[Feature Request] Support for Call of Cthulhu

[SsSanzo]

It would be amazing to add support for CALL of CTHULHU by adding automatically calculating and showing half and fifth values, and adding calculated traits (overwritable).

[lithedreamer]

If you're still interested, you might find my layout for Delta Green in discussion #41 useful, as they're sibling systems.

[sigrunixia]

Marking this as good first issue. While @lithedreamer's layout may fit the bill, this would be a great opportunity for someone to get their feet wet with some CSS.

[sigrunixia]

Converting this to a discussion.