docs: fix release-notes command in release guide (#13211)

The documented example still uses the removed --required-author flag and
misses --repo-path, which breaks with current release-notes binaries.
Update it to use the generate subcommand and point at the local checkout.

Signed-off-by: Kay Yan <kay.yan@daocloud.io>

OWNERS_ALIASES

@@ -8,6 +8,7 @@ aliases:
   kubespray-reviewers:
     - cyclinder
     - erikjiang
+    - guoard
     - mzaian
     - tico88612
     - vannten

RELEASE.md

@@ -58,7 +58,7 @@ You can create a release note with:
 export GITHUB_TOKEN=<your-github-token>
 export ORG=kubernetes-sigs
 export REPO=kubespray
-release-notes --start-sha <The start commit-id> --end-sha <The end commit-id> --dependencies=false --output=/tmp/kubespray-release-note --required-author=""
+release-notes generate --org "${ORG}" --repo "${REPO}" --repo-path "${PWD}" --start-sha <The start commit-id> --end-sha <The end commit-id> --dependencies=false --output=/tmp/kubespray-release-note
 ```
 
 If the release note file(/tmp/kubespray-release-note) contains "### Uncategorized" pull requests, those pull requests don't have a valid kind label(`kind/feature`, etc.).