dnslink-fetch: minor README improvement

plugins/dnslink-fetch/README.md

@@ -46,8 +46,8 @@ The request for `https://example.com/index.html` is being handled thus:
 
 1. scheme and domain removed: `index.html`
 2. two (based on `concurrency` setting) random alternative endpoints selected:
-   - `/https/example.net/alt-example`
-   - `/https/example.org`
+   - `dnslink=/https/example.net/alt-example`
+   - `dnslink=/https/example.org`
 3. resolve endpoint multiaddrs to URL of each endpoint:
    - `https://example.net/alt-example/`
    - `https://example.org/`