[DOCS] 프로젝트 README 문서 추가

[larama-C]

Added detailed project overview, main features, system architecture, tech stack, project structure, and backend team information.

🔗 관련 이슈

관련된 이슈 번호를 연결해주세요.
Close #이슈번호 를 쓰면 PR merge 시 자동으로 close 됩니다.

• Close #

🚀 PR 개요

이 PR이 어떤 변경을 포함하고 있는지 간단히 설명해주세요.

• Backend 프로젝트의 README 문서를 추가했습니다.
• 프로젝트 개요, 주요 기능, 시스템 아키텍처, 기술 스택, 프로젝트 구조, 팀 정보를 정리했습니다.

📌 변경 사항

주요 변경 내용을 체크리스트 형태로 정리해주세요.

• 기능 추가
• 버그 수정
• 리팩터링
• 문서 업데이트
• 테스트 추가/수정

🧪 테스트 방법

변경된 내용을 어떻게 테스트했는지 구체적으로 적어주세요.

📸 스크린샷 (선택)

UI 변경 또는 시각적으로 확인할 수 있는 변경이 있다면 첨부해주세요.

⚠️ 참고 사항

리뷰어가 알아야 할 사항이 있다면 자유롭게 작성해주세요.

• 프로젝트 소개 및 구조를 이해하기 쉽도록 README 문서를 정리했습니다. 피드백 환영입니다!

[github-actions]

Test Results

58 tests  ±0   58 ✅ ±0   10s ⏱️ ±0s
 9 suites ±0    0 💤 ±0 
 9 files   ±0    0 ❌ ±0 

Results for commit d19205a. ± Comparison against base commit 8c12237.

[github-actions]

⭐ JaCoCo Coverage

Line Coverage: 7.58%

📄 Coverage Details

Overall Line Coverage: 7.58% (549 covered / 7243 lines)

Package Summary (lowest first)

Package	Line %	Covered	Missed
com/back/web7_9_codecrete_be/domain/plans/controller	0.00%	0	63
com/back/web7_9_codecrete_be/domain/chats/entity	0.00%	0	4
com/back/web7_9_codecrete_be/domain/serverTime/entity	0.00%	0	9
com/back/web7_9_codecrete_be/domain/auth/entity	0.00%	0	0
com/back/web7_9_codecrete_be/domain/auth/service	0.00%	0	150
com/back/web7_9_codecrete_be/domain/artists/service/spotify/related/model	0.00%	0	5
com/back/web7_9_codecrete_be/domain/auth/controller	0.00%	0	24
com/back/web7_9_codecrete_be/domain/community/comment/controller	0.00%	0	10
com/back/web7_9_codecrete_be/domain/community/comment/entity	0.00%	0	12
com/back/web7_9_codecrete_be/domain/serverTime/controller	0.00%	0	3
com/back/web7_9_codecrete_be/domain/location/entity	0.00%	0	15
com/back/web7_9_codecrete_be/global/scheduler	0.00%	0	9
com/back/web7_9_codecrete_be/global/initData	0.00%	0	59
com/back/web7_9_codecrete_be/domain/email/entity	0.00%	0	6
com/back/web7_9_codecrete_be/domain/community/comment/service	0.00%	0	24
com/back/web7_9_codecrete_be/domain/artists/controller	0.00%	0	34
com/back/web7_9_codecrete_be/domain/community/post/controller	0.00%	0	63
com/back/web7_9_codecrete_be/domain/plans/service	0.20%	1	492
com/back/web7_9_codecrete_be/domain/artists/service/artistEnrichService	0.29%	4	1376
com/back/web7_9_codecrete_be/domain/community/post/service	0.36%	1	275
com/back/web7_9_codecrete_be/domain/artists/service	0.57%	4	694
com/back/web7_9_codecrete_be/global/wikidata	0.76%	5	652
com/back/web7_9_codecrete_be/domain/artists/service/spotify/related	0.87%	1	114
com/back/web7_9_codecrete_be/global/musicbrainz	0.99%	5	501
com/back/web7_9_codecrete_be/global/maniadb	1.22%	1	81
com/back/web7_9_codecrete_be/domain/artists/service/spotify/application	1.23%	1	80
com/back/web7_9_codecrete_be/domain/location/controller	1.35%	1	73
com/back/web7_9_codecrete_be/domain/email/service	1.61%	1	61
com/back/web7_9_codecrete_be/domain/chats/service	1.68%	2	117
com/back/web7_9_codecrete_be/global/flo	1.85%	1	53
com/back/web7_9_codecrete_be/domain/concerts/controller	2.13%	1	46
com/back/web7_9_codecrete_be/domain/concerts/repository	2.78%	1	35
com/back/web7_9_codecrete_be/domain/artists/service/spotify/genre	2.78%	1	35
com/back/web7_9_codecrete_be/global/storage	3.57%	2	54
com/back/web7_9_codecrete_be/global/websocket	4.65%	4	82
com/back/web7_9_codecrete_be/domain/serverTime/service	6.25%	3	45
com/back/web7_9_codecrete_be/domain/artists/entity	7.89%	6	70
com/back/web7_9_codecrete_be/global/redis	8.33%	2	22
com/back/web7_9_codecrete_be/global/rq	9.80%	5	46
com/back/web7_9_codecrete_be/domain/chats/controller	10.00%	2	18
com/back/web7_9_codecrete_be/domain/concerts/service	12.83%	83	564
com/back/web7_9_codecrete_be/domain/community/post/entity	14.13%	13	79
com/back/web7_9_codecrete_be/domain/users/util	14.29%	1	6
com/back/web7_9_codecrete_be/domain/plans/entity	18.10%	21	95
com/back/web7_9_codecrete_be/domain/users/service	29.91%	35	82
com/back/web7_9_codecrete_be/domain/location/service	31.25%	65	143
com/back/web7_9_codecrete_be/global/security	37.38%	40	67
com/back/web7_9_codecrete_be/domain/concerts/entity	37.63%	35	58
com/back/web7_9_codecrete_be/domain/artists/service/spotify/rate_limit	38.57%	27	43
com/back/web7_9_codecrete_be/domain/users/controller	51.61%	16	15
com/back/web7_9_codecrete_be/domain/users/entity	64.81%	35	19
com/back/web7_9_codecrete_be/global/rsData	81.82%	9	2
com/back/web7_9_codecrete_be/global/spotify	87.50%	35	5
com/back/web7_9_codecrete_be/domain/artists/service/spotify/cache	93.55%	58	4
com/back/web7_9_codecrete_be/global/doc	100.00%	17	0
com/back/web7_9_codecrete_be/global/aspect	100.00%	4	0

Lowest Covered Classes (Top 20)

Class	Line %	Covered	Missed
com.back.web7_9_codecrete_be.domain.artists.service.artistEnrichService.EnrichStepExecutor	0.00%	0	183
com.back.web7_9_codecrete_be.domain.artists.service.ArtistService	0.00%	0	106
com.back.web7_9_codecrete_be.domain.auth.service.AuthService	0.00%	0	88
com.back.web7_9_codecrete_be.domain.plans.controller.PlanController	0.00%	0	63
com.back.web7_9_codecrete_be.global.initData.BaseInitData	0.00%	0	59
com.back.web7_9_codecrete_be.domain.plans.entity.Schedule	0.00%	0	54
com.back.web7_9_codecrete_be.domain.community.post.service.JoinPostService	0.00%	0	47
com.back.web7_9_codecrete_be.domain.community.post.service.MyCommunityService	0.00%	0	47
com.back.web7_9_codecrete_be.domain.community.post.service.PostService	0.00%	0	44
com.back.web7_9_codecrete_be.domain.location.service.PlanCostTimeService	0.00%	0	43
com.back.web7_9_codecrete_be.domain.artists.entity.Artist	0.00%	0	40
com.back.web7_9_codecrete_be.domain.chats.service.ChatPolicyService	0.00%	0	38
com.back.web7_9_codecrete_be.global.security.JwtTokenProvider	0.00%	0	37
com.back.web7_9_codecrete_be.domain.location.service.LocationService	0.00%	0	30
com.back.web7_9_codecrete_be.domain.plans.entity.Plan	0.00%	0	30
com.back.web7_9_codecrete_be.domain.auth.service.TokenService	0.00%	0	26
com.back.web7_9_codecrete_be.domain.artists.controller.ArtistsController	0.00%	0	26
com.back.web7_9_codecrete_be.domain.auth.controller.AuthController	0.00%	0	24
com.back.web7_9_codecrete_be.domain.community.post.entity.Post	0.00%	0	24
com.back.web7_9_codecrete_be.domain.community.comment.service.CommentService	0.00%	0	24

Changed Classes (from this PR)

Source (PR)	Class Prefix	Line %	Covered	Missed
src/main/java/com/back/web7_9_codecrete_be/domain/community/comment/dto/response/CommentResponse.java	com.back.web7_9_codecrete_be.domain.community.comment.dto.response.CommentResponse	0.00%	0	0

🔗 Full HTML report: See artifact jacoco-full-html on this run → https://github.com/prgrms-web-devcourse-final-project/WEB7_9_codecrete_BE/actions/runs/23186363674