新增 Doocs 开源组织 favicon

* How to join: see https://doocs.github.io/#/?id=how-to-join
* GitHub Page: https://doocs.github.io
* Gitee Page: https://doocs.gitee.io

更新封面和首页信息

close #93

修改仓库主语言显示，关闭 Issue #92

* GitHub Page: https://doocs.github.io/advanced-java
* Gitee Page: https://doocs.gitee.io/advanced-java
* Author: https://github.com/yanglbme

部分文件移动至新的文件夹，项目结构更简洁美观

* 更新 SUMMARY 目录
* 关闭 Issue #91
* 移除 sw.js 文件
* 修正 from-readers/README.md 中的错误链接

禁止直接拷贝文档和图片而不注明出处，请尊重别人的劳动成果。
本仓库由 @yanglbme 长期更新维护，GitHub 见 https://github.com/yanglbme

* 图片优化
* Issue(#89) 关闭

更新文档描述

* 更新文档首页 footer 和 navbar
* 关闭无效 pull request

[ImgBot] Optimize images

*Total -- 370.62kb -> 317.97kb (14.21%)

/images/BRP.jpg -- 8.95kb -> 6.71kb (25.01%)
/docs/high-availability/images/BRP.jpg -- 8.95kb -> 6.71kb (25.01%)
/images/Sentinel-VS-Hystrix.jpg -- 58.11kb -> 48.47kb (16.59%)
/docs/high-availability/images/Sentinel-VS-Hystrix.jpg -- 58.11kb -> 48.47kb (16.59%)
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/docs/high-availability/images/Sentinel-Dashboard.jpg -- 66.08kb -> 58.68kb (11.2%)
Signed-off-by: NImgBotApp <ImgBotHelp@gmail.com>

Sentinel 和 Hystrix，该如何做技术选型？
本文由 Doocs 开源组织(https://github.com/doocs)整理自阿里巴巴中间件团队，供各位朋友学习了解，鼓励大家使用阿里开源组件。

* close #84 
* close #85

* close #82 
* 更新 Redis 单线程模型描述，读者可以参考《Redis 设计与实现》进行系统学习。
* See https://github.com/doocs/technical-books#database

close #80

* close #64
* update copyright

* close #75
* close #76

* close #73
* close #74

See https://github.com/doocs/advanced-java/blob/master/docs/from-readers/README.md

更新数据库中间件描述信息，详情请看：https://github.com/doocs/advanced-java/blob/master/docs/high-concurrency/database-shard.md

* fix typo in distributed-lock-redis-vs-zookeeper.md
* update redis-single-thread-model.md

更新 Redis 分布式锁相关描述
详细说明查看：https://github.com/doocs/advanced-java/blob/master/docs/distributed-system/distributed-lock-redis-vs-zookeeper.md

更新 Dubbo 集群容错策略相关描述
详细说明查看：https://github.com/doocs/advanced-java/blob/master/docs/distributed-system/dubbo-load-balancing.md

* fix typo and close #68
* thanks @dusked

fix #67, see https://github.com/doocs/advanced-java/blob/master/docs/high-concurrency/how-to-ensure-high-availability-of-message-queues.md