Update PKGBUILD

Bump to 3.5, install the sample config, and quote variables
separately from literal path parts.

PKGBUILD

@@ -3,11 +3,11 @@
 # Maintainer: Daniele Fucini <dfucini [at] gmail [dot] com>
 
 pkgname=update-notify
-pkgver=3.4
+pkgver=3.5
 pkgrel=1
 pkgdesc='Notify when updates are available'
 arch=('any')
-url="https://git.shouldnt.work/fuxino/${pkgname}"
+url="https://git.shouldnt.work/fuxino/$pkgname"
 license=('GPL-3.0-or-later')
 depends=('pacman-contrib'
          'libnotify')
@@ -15,15 +15,16 @@ makedepends=('git')
 optdepends=('aurutils: to check AUR packages in the local repo for updates'
             'fwupd: to check for firmware updates'
             'git-monitor: to check git repos for updates')
-source=("git+${url}?signed#tag=${pkgver}")
+source=("git+$url?signed#tag=$pkgver")
 validpgpkeys=('7E12BC1FF3B6EDB2CD8053EB981A2B2A3BBF5514')
-sha256sums=('12a68498d50871264f4a0ed082ff29a361676cf134c43520f98ee3f287e45509')
+sha256sums=('6620f528f9114b0e17723322558c7ba484c236ba9a7ece8b754f25ade84883ff')
 
 package()
 {
-    cd "${srcdir}/${pkgname}"
-    install -Dm755 "${pkgname}" "${pkgdir}/usr/bin/${pkgname}"
-    install -Dm644 "${pkgname}.service" "${pkgdir}/usr/lib/systemd/user/${pkgname}.service"
-    install -Dm644 "${pkgname}.timer" "${pkgdir}/usr/lib/systemd/user/${pkgname}.timer"
-    install -Dm644 README.md "${pkgdir}/usr/share/doc/${pkgname}/README.md"
+    cd "$srcdir"/"$pkgname"
+    install -Dm755 "$pkgname" "$pkgdir"/usr/bin/"$pkgname"
+    install -Dm644 "$pkgname".service "$pkgdir"/usr/lib/systemd/user/"$pkgname".service
+    install -Dm644 "$pkgname".timer "$pkgdir"/usr/lib/systemd/user/"$pkgname".timer
+    install -Dm644 README.md "$pkgdir"/usr/share/doc/"$pkgname"/README.md
+    install -Dm644 config.example "$pkgdir"/usr/share/doc/"$pkgname"/config.example
 }