Chain lightning/doc

• Chain Lightning is a comparatively rare CBM obtainable from zombie bionic-operators, technicians, and scientists, as well as being lootable in labs.
• The Chain Lightning CBM allows a player to channel stored bionic power into a potent AOE attack, which creates a briefly persisting (3 turns) cloud of damaging electricity. It is capable of damaging the player if used in melee, or if they choose to walk into the cloud before it disperses. Its large cost can result in slow duty cycles for new characters, but it can still do considerable damage to a mob of zombies even in single uses.
• Uses the chain lightning pseudo weapon.