add: all (android package manager)
	new file:   android/03_android_package_manager.md
	new file:   assets/pkg_install.uml
	modified:   杂类/01_定位SDK大小对比及优化分析.md
	modified:   编程语言/03_jls_01读书笔记.md
	new file:   读书笔记/02_挖一口属于自己的井.md