[FEATURE] Starting line items & clear inventory

[diademiemi]

Starting lines will have the option to give items on start, this can be useful for races that could require players to have food, a carrot on a stick or an elytra.
If the item specified is an armor item, it will automatically equip it to the players if there is no armor equipped already.
ln line a_start_line item add carrot_on_a_stick
The quantity of the item can also be selected
ln line a_start_line item add steak 64
If the item is an armor item, equip it
ln line a_start_line item add elytra
Since this information could quickly clog up a lines info page, it will be available in a page ln line a_start_line info items
Prizes are numbered and are given out in order, so this should be able to determine the order of the hotbar too.
Prizes can be removed with
ln line a_start_line item 1 remove
It should also be possible to modify an item after it has been set with
ln line a_start_line item 1 steak 32

The line should also have an option to clear the players inventory before starting, this is done before giving items, so it is possible to completely specify what a player should have.
ln line a_start_line option clearinventory true
The plugin will not keep track of inventories and items will not be returned after line completion. This is beyond the scope of the plugin, so only use this feature in combination with other plugins or in game worlds where players inventories aren't important.