Adding `Equipment` and `ActionBar` sections to README
Adding horizontal rules to README
`ActionItem`
Recreating `Icons`, updating Scene
Updating Unity Package
`ActionItem` now takes GameObject on `Use()`
Recreating `Icons`, updating Scene
Updating Unity Package
Merge branch 'master' of https://github.com/adampassey/bitsy
Updating `.gitignore`, including all icons
Items no longer intercept drag event from a window being dragged
* Fixed all warnings
Default Handlers for `UI.Draggable` and `UI.Slot`

* These default handlers are both responsible for focusing on the parent
window on `Hover`
* Handlers for `Inventory`, `Equipment`, and `ActionBar` have all been
converted to extend these default handlers
Code-formatter update for namespace and class braces
Updating README, `ActionItem`s can be destroyed on use
Initial pass at Stackable Items

* If `DraggableHandler`s return null on `ItemDropped(DraggedItem item)`,
the currently dragged item will be consumed
* Adding several stackable items to main scene for testing
Inventory now auto-stacks Stackable items

* Dropping stacks of items also separates those items
* `DroppableScreenOverlay` will only drop an item if `Item.Drop()`
returns `true`
Stacks can now be merged properly

* Stacks on stacks
Updating Package
Stackable items can now be swapped in inventory
`ActionItem` is now a standalone component

* This allows more flexibility in what can be placed in the `ActionBar`
* All stackable red potions now have an `ActionItem` component
* Swords now have an `ActionItem` component
* Minimal cleanup in `ActionBarGUI`