doc: clarify http2.connect authority details

Fixes: #31827

PR-URL: #31828
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Signed-off-by: James M Snell <jasnell@gmail.com>

doc/api/http2.md

@@ -2206,7 +2206,11 @@ changes:
                  128 header pairs.
 -->
 
-* `authority` {string|URL}
+* `authority` {string|URL} The remote HTTP/2 server to connect to. This must
+  be in the form of a minimal, valid URL with the `http://` or `https://`
+  prefix, host name, and IP port (if a non-default port is used). Userinfo
+  (user ID and password), path, querystring, and fragment details in the
+  URL will be ignored.
 * `options` {Object}
   * `maxDeflateDynamicTableSize` {number} Sets the maximum dynamic table size
     for deflating header fields. **Default:** `4Kib`.