Refactor: deplacer backend dans apps/backend

apps/backend/app/main.py

@@ -0,0 +1,9 @@
+from fastapi import FastAPI
+
+from app.routers import projects, experiences, skills
+
+app = FastAPI()
+
+app.include_router(projects.router, prefix="/api")
+app.include_router(experiences.router, prefix="/api")
+app.include_router(skills.router, prefix="/api")