Add speed boost item

[rowan04]

• speed boost spawns randomly in an item spawning slot
• speed boost can be picked up by player
• when activated, player moves twice as fast
• current issues:
• doesn't deactivate
• i think it might be able to spawn in same location as time freeze
• doesn't have inventory image yet

[rowan04]

this isnt ready for review yet tho

[rowan04]

fixed conflict