build(PKGBUILD): add PKGBUILD for AUR

dist/aur/PKGBUILD

+# Maintainer: TheBitStick <thebitstick@tfwno.gf>
+pkgname=journable-git
+pkgver=0.0.1
+pkgrel=1
+pkgdesc="A simple bullet journal."
+arch=(any)
+url="https://gitlab.gnome.org/BjoernDaase/journable"
+license=('GPL3')
+depends=('gtk3' 'appstream-glib' 'python')
+makedepends=('git' 'meson' 'cmake')
+checkdepends=()
+optdepends=()
+provides=(${pkgname%-git})
+conflicts=(${pkgname%-git})
+backup=()
+options=()
+source=("git+${url}.git")
+md5sums=('SKIP')
+
+build() {
+  meson --prefix=/usr --buildtype=plain journable build
+  ninja -C build
+}
+
+package() {
+  DESTDIR="$pkgdir" ninja -C build install
+}
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