Fix docs typo in the certutil CSR mode
Changes the mention of `cert` to `csr`.
@@ -103,7 +103,7 @@ which prompts you for details about each instance. Alternatively, you can use
the `--in` parameter to specify a YAML file that contains details about the
instances.
-The `cert` mode produces a single zip file which contains the CSRs and the
+The `csr` mode produces a single zip file which contains the CSRs and the
private keys for each instance. Each CSR is provided as a standard PEM
encoding of a PKCS#10 CSR. Each key is provided as a PEM encoding of an RSA
private key.
