0.4.0

🍀 Added

• Added a new Blocktad drawing format. It works similarly to Octads, but uses blocks instead of braille characters

⚒️ Changed

• Reworked the layer API into a more memory safe form
• Improved stability and performance of the diffing step (@airblast-dev)
• Removed unnecessary allocations (@airblast-dev)

💥 Breaking

• Layer is now reserved for internal use, the new public API uses LayerIndex and the create_layer() factory
• Changed drawing function first args from &mut Layer to &mut Engine and LayerIndex
• Removed Color::NO_COLOR in favor of Attributes::NO_FG_COLOR and Attributes::NO_BG_COLOR