General English fixes (#52)

* Speeling fixes

* Speeling/capitalisation

* More speeling

* Label grammar consistency

* Consistency

* Phrasing

* Consistency

* Clarity of const

* Consistency

* Consistency

* Speeling

* Apostrophes: check whether they need escaping

* Capitalisation (more apostrophes need checking)

* Americanisation

* Clarity

* Contraction

* Clarity

* Speeling

Addons/Commands/kill.lua

@@ -8,7 +8,7 @@ Discord: https://discord.gg/r6dC2uK
 ]]
 --Please Only Edit Below This Line-----------------------------------------------------------
 
-commands.add_command('kill', 'Kills a player. Must be either yourself (/kill self) or a person of a lower rank.', {'player'}, function(event,args)
+commands.add_command('kill', 'Kills a player. Must be either yourself (/kill self) or a person of a lower rank', {'player'}, function(event,args)
     local _player = Game.get_player(event)
     local player = Game.get_player(args.player)
     if args.player ~= 'self' and not player then player_return({'commands.invalid-player',args.player}) return commands.error end