Update: Firefoxの最低バージョン&更新チェックURLなどの指定

src/manifest.json

@@ -75,5 +75,12 @@
     "/view/search.html",
     "/view/sidemenu.html",
     "/view/thread.html"
-  ]
+  ],
+  "applications": {
+    "gecko": {
+      "id": "readcrx2@read.crx",
+      "strict_min_version": "58.0",
+      "update_url": "https://readcrx-2.github.io/read.crx-2/updates_firefox.xml"
+    }
+  }
 }