Add proficiencies to the Knight class

[Ork]

Now with the onset of .haks, the Knight class is sorely in need of proficiencies that match the class's theme.

The knight class should gain proficiencies in:
Martial weapon
Simple weapon
Light armor
Medium armor
Heavy armor &
Shield

[Irongron]

I know this class is already powerful, but approved for all but heavy armour, as is thematically fitting.