v0.3

• Enemy Attack Warning: Now you can select a unit and right-drag the mouse to preview attack ranges of the selected unit (red dots) and enemy units (exclamation marks).
• Better UI: Rectangle rendering on the map has been enhanced for better visual clarity.
• Blitz: Some units (now commando) with the blitz trait gain an extra movement after attack.
• Documentation and Code Improvement: Add Project Guide and revise some parts of the code to make it more consistent and readable.