Update README.md
update 02/13
02/13 Inheritance Done!
update README.md
Update README.md
update 02/13
02/13 Inheritance Done!
update README.md
Merge branch 'dev' of github.com:Hawstein/the-swift-programming-language-in-chinese into dev
Merge pull request #52 from Hawstein/dev

[ 继承 ] 认领 “继承” 一节