Update mkdocs.yml

add redirect to fix 404

Author: hsutaiyu

mkdocs.yml

@@ -682,6 +682,7 @@ plugins:
         'pos/how-to/operate-validator-node/validator-best-practices.md': 'pos/how-to/validator/validator-best-practices.md'
         'pos/how-to/operate-validator-node/validator-commission-operations.md': 'pos/how-to/operate-validator-node/next-steps.md'
         'pos/how-to/operate-validator-node/validator-staking-operations.md': 'pos/how-to/operate-validator-node/next-steps.md'
+        'pos/how-to/operating/validator-node/index.md': 'pos/how-to/operate-validator-node/next-steps.md'