Update Hello-world.md

Update Example of python.
Merge pull request #6 from alvayang/master

Update Hello-world.md
Update Hello-world.md
6.1
Merge branch 'master' of github.com:zhuangbiaowei/learn-with-open-source
random
add image
2048-2
add some contents
2048 step 1
Merge pull request #7 from wgwang/master

add some contents
添加 《关于程序员学英语的经验》 的 URL
Merge pull request #10 from Yixiaohan/patch-1

添加 《关于程序员学英语的经验》 的 URL