Add missing package.json properties

Author: samstarling

incident/package.json

@@ -10,9 +10,14 @@
     "types": "dist/index.d.ts"
   },
   "backstage": {
-    "role": "frontend-plugin"
+    "pluginId": "incident-io",
+    "role": "frontend-plugin",
+    "pluginPackages": [
+      "@incident-io/backstage"
+    ]
   },
   "configSchema": "config.d.ts",
+  "sideEffects": false,
   "scripts": {
     "start": "backstage-cli package start",
     "build": "backstage-cli package build",
@@ -73,4 +78,4 @@
     "url": "https://github.com/incident-io/backstage-plugins.git",
     "directory": "incident"
   }
-}
+}