feat: add cli flags

example/main.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"net/http"
+	"time"
+
+	npmproxy "github.com/emeralt/npm-cache-proxy/proxy"
+	"github.com/go-redis/redis"
+)
+
+func main() {
+	proxy := npmproxy.Proxy{
+		RedisClient: redis.NewClient(&redis.Options{
+			Addr:     "localhost:6379",
+			DB:       0,
+			Password: "",
+		}),
+		HttpClient: &http.Client{},
+		GetOptions: func() (npmproxy.Options, error) {
+			return npmproxy.Options{
+				RedisPrefix:        "ncp-",
+				RedisExpireTimeout: 1 * time.Hour,
+				UpstreamAddress:    "https://registry.npmjs.org",
+			}, nil
+		},
+	}
+
+	proxy.Server(npmproxy.ServerOptions{
+		ListenAddress: "localhost:8080",
+	}).ListenAndServe()
+}