add csv reading, routing

internal/cli.go

@@ -0,0 +1,7 @@
+package internal
+
+type CLI struct {
+	File string `arg:"" name:"file" short:"f" help:"Path to CSV redirects file." type:"path"`
+	Host string `name:"host" help:"HTTP listen host." default:"${host}"`
+	Port string `name:"port" short:"p" help:"HTTP listen port." default:"${port}"`
+}