Translate task: content/projects/gsoc/*

[node]

Subtasks :

• [ ] gson2016
• [ ] gson2017
• [ ] gson2018-project-ideas
• [ ] mentors
• [ ] students

[node]

@cizezsy 子任务可以分别提交PR，这样比较快，避免一次提交太多文件，review压力也大 :)

[cizezsy]

@node OK :P