use go:embed for static resources (#1107)

* feat: use go:embed to embed static files

* ci: fix broken test

* docs: update readme.md

* chore: remove statik

* feat: simplify code

Co-authored-by: AaronLiu <abslant@126.com>

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"embed"
 	"flag"
 
 	"github.com/cloudreve/Cloudreve/v3/bootstrap"
@@ -15,6 +16,9 @@ var (
 	scriptName string
 )
 
+//go:embed assets/build
+var StaticEmbed embed.FS
+
 func init() {
 	flag.StringVar(&confPath, "c", util.RelativePath("conf.ini"), "配置文件路径")
 	flag.BoolVar(&isEject, "eject", false, "导出内置静态资源")