[ImgBot] Optimize images

*Total -- 3,590.56kb -> 3,268.15kb (8.98%)

/media/pictures/kafka/生产者和消费者.png -- 49.87kb -> 36.48kb (26.84%)
/media/pictures/kafka/发送消息.png -- 134.63kb -> 102.35kb (23.97%)
/media/pictures/kafka/启动服务.png -- 495.87kb -> 381.17kb (23.13%)
/media/pictures/kafka/segment是kafka文件存储的最小单位.png -- 89.19kb -> 72.00kb (19.27%)
/media/pictures/kafka/kafka存在文件系统上.png -- 91.01kb -> 74.72kb (17.9%)
/media/pictures/kafka/主题与分区.png -- 71.15kb -> 59.05kb (17.01%)
/media/pictures/kafka/消费者设计概要3.png -- 73.29kb -> 61.70kb (15.82%)
/media/pictures/kafka/消费者设计概要5.png -- 73.29kb -> 61.70kb (15.82%)
/media/pictures/kafka/Broker和集群.png -- 134.03kb -> 113.60kb (15.24%)
/media/pictures/kafka/消费者设计概要4.png -- 52.77kb -> 45.40kb (13.95%)
/media/pictures/kafka/消费者设计概要2.png -- 47.27kb -> 41.60kb (11.99%)
/media/pictures/kafka/生产者设计概要.png -- 82.82kb -> 73.99kb (10.67%)
/media/pictures/kafka/Partition与消费模型.png -- 19.48kb -> 17.46kb (10.4%)
/media/pictures/kafka/消费者设计概要1.png -- 40.72kb -> 36.94kb (9.29%)
/media/sponsor/WechatIMG143.jpeg -- 50.88kb -> 47.97kb (5.71%)
/media/pictures/rostyslav-savchyn-5joK905gcGc-unsplash.jpg -- 2,084.30kb -> 2,042.02kb (2.03%)

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