Add appstream metadata file

data/meson.build

@@ -22,3 +22,28 @@ install_data(
   desktop_file,
   install_dir: datadir / 'applications'
 )
+
+
+appdata_conf = configuration_data()
+appdata_conf.set('app-id', base_id)
+appdata_file = configure_file(
+  input: '@0@.metainfo.xml.in'.format(base_id),
+  output: '@BASENAME@',
+  configuration: appdata_conf
+)
+
+# Validate Appdata
+if appstream_util.found()
+  test(
+    'validate-appdata',
+    appstream_util,
+    args: [
+      'validate', '--nonet', appdata_file
+    ],
+  )
+endif
+
+install_data(
+  appdata_file,
+  install_dir: datadir / 'metainfo'
+)