fix typo in doc. (#9728)

Signed-off-by: yanggang <gang.yang@daocloud.io>

README.md

@@ -45,7 +45,7 @@ Note: When Ansible is already installed via system packages on the control node,
 Python packages installed via `sudo pip install -r requirements.txt` will go to
 a different directory tree (e.g. `/usr/local/lib/python2.7/dist-packages` on
 Ubuntu) from Ansible's (e.g. `/usr/lib/python2.7/dist-packages/ansible` still on
-buntu). As a consequence, the `ansible-playbook` command will fail with:
+Ubuntu). As a consequence, the `ansible-playbook` command will fail with:
 
 ```raw
 ERROR! no action detected in task. This often indicates a misspelled module name, or incorrect module path.

docs/upgrades/migrate_docker2containerd.md

@@ -66,7 +66,7 @@ apt-get install pigz
 ### 5) Run `cluster.yml` playbook with `--limit`
 
 ```commandline
-ansible-playbook cluster.yml -i inventory/sample/hosts.ini cluster.yml --limit=NODENAME
+ansible-playbook -i inventory/sample/hosts.ini cluster.yml --limit=NODENAME
 ```
 
 This effectively reinstalls containerd and seems to place all config files in the right place. When this completes, kubelet will immediately pick up the new container engine and start spinning up DaemonSets and kube-system Pods.