docs(markdownlint): enable autofixable rules and normalize links

docs/channels/bluebubbles.md

@@ -27,6 +27,7 @@ Status: bundled plugin that talks to the BlueBubbles macOS server over HTTP. **R
 1. Install the BlueBubbles server on your Mac (follow the instructions at [bluebubbles.app/install](https://bluebubbles.app/install)).
 2. In the BlueBubbles config, enable the web API and set a password.
 3. Run `openclaw onboard` and select BlueBubbles, or configure manually:
+
    ```json5
    {
      channels: {
@@ -39,6 +40,7 @@ Status: bundled plugin that talks to the BlueBubbles macOS server over HTTP. **R
      },
    }
    ```
+
 4. Point BlueBubbles webhooks to your gateway (example: `https://your-gateway-host:3000/bluebubbles-webhook?password=<password>`).
 5. Start the gateway; it will register the webhook handler and start pairing.