Added Apple web-app meta tag #358 (#359)

* Added Apple web-app meta tag #358

* Added manifest file for web app

* Changed manifest to use template #358

* Small tweaks, add tests

---------

Co-authored-by: Sascha Ißbrücker <sascha.issbruecker@gmail.com>

bookmarks/tests/test_metadata_view.py

@@ -0,0 +1,33 @@
+from django.test import TestCase, override_settings
+
+
+class MetadataViewTestCase(TestCase):
+
+    def test_default_manifest(self):
+        response = self.client.get("/manifest.json")
+
+        self.assertEqual(response.status_code, 200)
+
+        response_body = response.json()
+        expected_body = {
+            "short_name": "linkding",
+            "start_url": "bookmarks",
+            "display": "standalone",
+            "scope": "/"
+        }
+        self.assertDictEqual(response_body, expected_body)
+
+    @override_settings(LD_CONTEXT_PATH="linkding/")
+    def test_manifest_respects_context_path(self):
+        response = self.client.get("/manifest.json")
+
+        self.assertEqual(response.status_code, 200)
+
+        response_body = response.json()
+        expected_body = {
+            "short_name": "linkding",
+            "start_url": "bookmarks",
+            "display": "standalone",
+            "scope": "/linkding/"
+        }
+        self.assertDictEqual(response_body, expected_body)