kopia: add bash and zsh completions.

srcpkgs/kopia/template

@@ -1,8 +1,9 @@
 # Template file for 'kopia'
 pkgname=kopia
 version=0.8.4
-revision=1
+revision=2
 build_style=go
+build_helper="qemu"
 go_import_path=github.com/kopia/kopia
 go_ldflags="-X ${go_import_path}/repo.BuildVersion=${version}
  -X '${go_import_path}/repo.BuildInfo=Void Linux'"
@@ -12,3 +13,10 @@ license="Apache-2.0"
 homepage="https://kopia.io/"
 distfiles="https://github.com/kopia/kopia/archive/v${version}.tar.gz"
 checksum=8e2663546fb426faacb4dd9425cdbba4fa2e8ca5df0aac0545d216c8e57d40ef
+
+post_install() {
+	for shell in bash zsh; do
+		vtargetrun ${DESTDIR}/usr/bin/${pkgname} --completion-script-${shell} > completions.${shell}
+		vcompletion completions.${shell} ${shell}
+	done
+}