chore: add first handlers

backend/internal/storage/repository.go

@@ -0,0 +1,15 @@
+package storage
+
+import (
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+type Repository struct {
+	pool *pgxpool.Pool
+}
+
+func NewRepository(pool *pgxpool.Pool) *Repository {
+	return &Repository{
+		pool: pool,
+	}
+}