API Documentation - Challenge

1. POST /api/challenge/getChallenge
   
2. 챌린지 상세 정보 조회
   
3. input(body)
   javascript { "challengeName": String }
4. POST /api/challenge/addChallenge
   
5. 챌린지 추가
   
6. input(body) javascript { "challengeName":String, "startDate":Date, "endDate":Date, "durationPerSession": String, // "1d"=1 day, "2w"=2 weeks, "3m"=3 months "goalPerSession":Number }
7. GET /api/challenge/list/:status
   
8. 챌린지 목록 조회
9. input(parameter) status=(one of ["all","enrolled","progress","end"])
10. POST /api/challenge/participate
    
11. 챌린지 참가
12. input(body) javascript { "username":String, "challengeName":String }