epm play sing-box: add sing-box universal proxy platform

play.d/sing-box.sh

+#!/bin/sh
+
+PKGNAME=sing-box
+SUPPORTEDARCHES="x86_64 aarch64 armhf"
+VERSION="$2"
+DESCRIPTION="The universal proxy platform (sing-box)"
+URL="https://github.com/SagerNet/sing-box"
+
+. $(dirname $0)/common.sh
+
+arch="$(epm print info --debian-arch)"
+
+if [ "$VERSION" = "*" ] ; then
+    PKGURL=$(get_github_url "https://github.com/SagerNet/sing-box/" "sing-box_${VERSION}_linux_$arch.deb")
+else
+    PKGURL="https://github.com/SagerNet/sing-box/releases/download/v$VERSION/sing-box_${VERSION}_linux_$arch.deb"
+fi
+
+install_pkgurl