SmrShip: document and rename loadWeapon
SmrShip: document and rename loadWeapon

* Rename loadWeapon -> loadWeapons
* Add docstring to clarify what this method does

This method is responsible for initializing the SmrWeapon array
for weapons that are already onboard this ship. The previous
version was easy to confuse with `addWeapon`.

smrealms/smr,smrealms/smr,hemberger/smr,hemberger/smr,hemberger/smr,smrealms/smr,hemberger/smr