Update PKGBUILD

Fixed so that it does install. Added default pkgver() from arch wiki.

arch/PKGBUILD

@@ -7,10 +7,16 @@ pkgdesc='pure prompt for zsh'
 arch=('any')
 url='https://github.com/sindresorhus/pure'
 license=('MIT')
-source=(pure.zsh)
+source=($pkgname::${url//https/git})
+md5sums=('SKIP')
+
+pkgver() {
+  cd "$srcdir/$pkgname"
+  git describe --long | sed -r 's/([^-]*-g)/r\1/;s/-/./g'
+}
 
 package() {
+  cd $srcdir/$pkgname
   install -Dm644 pure.zsh \
     "$pkgdir/usr/share/zsh/functions/Prompts/prompt_pure_setup"
 }
-md5sums=('673c5d65495ba6942938925ab4cff2d8')