Deleted duplicate sentence and corrected typo (kubernetes#17902)

* Corrected the typo of 'chck' with 'check'

* Removed the duplicate sentence

content/en/docs/tasks/administer-cluster/kubeadm/kubeadm-certs.md

@@ -200,8 +200,6 @@ Certificates can be renewed with `kubeadm alpha certs renew --csr-only`.
 As with `kubeadm init`, an output directory can be specified with the `--csr-dir` flag.
 To use the new certificates, copy the signed certificate and private key into the PKI directory (by default `/etc/kubernetes/pki`)
 
-A CSR contains a certificate's name, domain(s), and IPs, but it does not specify usages.
-
 A CSR contains a certificate's name, domains, and IPs, but it does not specify usages.
 It is the responsibility of the CA to specify [the correct cert usages][cert-table] when issuing a certificate.
 

content/en/docs/tasks/extend-kubectl/kubectl-plugins.md

@@ -168,7 +168,7 @@ sudo chmod +x ./kubectl-foo-bar-baz
 # "install" your plugin by moving it to a directory in your $PATH
 sudo mv ./kubectl-foo-bar-baz /usr/local/bin
 
-# chck that kubectl recognizes your plugin
+# check that kubectl recognizes your plugin
 kubectl plugin list
 ```