1. Add new trailer to tank workshop ● Trailer can only be added to hull or another trailer ● Trailer can be deattached or reattached during battle ● Trailer can be scaled 2. Ammunition optimization ● The default range coefficient of damage and penetration has been changed from 0.75~1.25 to 0.95~1.05, and added to the battleConf.yaml file, which is convenient for players to customize configuration ● AP, HE shells Add the option of whether to decay with distance, AP is enabled by default, and shells to anti-aircraft vehicles are disabled. HE are also disabled by default. Decay factor with distance changed from 0.1 to 0.05 ● Normal distribution standard deviation adjustment ● HE Explosion range is expanded 3. Crosshair size can be loaded from conf