a fix for ki focus

i suggest that ki focus not be an implement. instead, make it a unique category of items that strictly enhances other items that are weapons.

so, for both monk and assassins, instead of:

Implement: Ki focuses, weapons with which you have proficiency

the applicable line would read:

Implement: Weapons with which you have proficiency.

next, i would suggest that when a monk/assassin makes an attack, whether a weapon attack or an implement attack, the monk/assassin must use a weapon to do so, but can choose to apply a ki focus to the weapon in lieu of the weapon's own properties.