fix(windows): use the app icon for the NSIS installer and uninstaller (#275)

The NSIS installer and uninstaller showed the default NSIS icon because tauri.windows.conf.json set no installerIcon/uninstallerIcon; both now use icons/icon.ico (merged into the base bundle config as a JSON merge patch).

Co-authored-by: youngtseup <[email protected]>

src-tauri/tauri.windows.conf.json

@@ -14,5 +14,13 @@
         "dragDropEnabled": true
       }
     ]
+  },
+  "bundle": {
+    "windows": {
+      "nsis": {
+        "installerIcon": "icons/icon.ico",
+        "uninstallerIcon": "icons/icon.ico"
+      }
+    }
   }
 }