feat(secrets-manager): add docs

Author: s-inter

docs/stackit_secrets-manager_instance_create.md

@@ -18,14 +18,21 @@ stackit secrets-manager instance create [flags]
 
   Create a Secrets Manager instance with name "my-instance" and specify IP range which is allowed to access it
   $ stackit secrets-manager instance create --name my-instance --acl 1.2.3.0/24
+
+  Create a Secrets Manager instance with name "my-instance" and configure KMS key options
+  $ stackit secrets-manager instance create --name my-instance --kms-key-id key-id --kms-keyring-id keyring-id --kms-key-version 1 --kms-service-account-email my-service-account-1234567@sa.stackit.cloud
 ```
 
 ### Options
 
 ```
-      --acl strings   List of IP networks in CIDR notation which are allowed to access this instance (default [])
-  -h, --help          Help for "stackit secrets-manager instance create"
-  -n, --name string   Instance name
+      --acl strings                        List of IP networks in CIDR notation which are allowed to access this instance (default [])
+  -h, --help                               Help for "stackit secrets-manager instance create"
+      --kms-key-id string                  ID of the KMS key to use for encryption
+      --kms-key-version int                Version of the KMS key
+      --kms-keyring-id string              ID of the KMS key ring
+      --kms-service-account-email string   Service account email for KMS access
+  -n, --name string                        Instance name
 ```
 
 ### Options inherited from parent commands

docs/stackit_secrets-manager_instance_update.md

@@ -15,13 +15,20 @@ stackit secrets-manager instance update INSTANCE_ID [flags]
 ```
   Update the range of IPs allowed to access a Secrets Manager instance with ID "xxx"
   $ stackit secrets-manager instance update xxx --acl 1.2.3.0/24
+
+  Update the KMS key settings of a Secrets Manager instance with ID "xxx"
+  $ stackit secrets-manager instance update xxx --kms-key-id key-id --kms-keyring-id keyring-id --kms-key-version 1 --kms-service-account-email my-service-account-1234567@sa.stackit.cloud
 ```
 
 ### Options
 
 ```
-      --acl strings   List of IP networks in CIDR notation which are allowed to access this instance (default [])
-  -h, --help          Help for "stackit secrets-manager instance update"
+      --acl strings                        List of IP networks in CIDR notation which are allowed to access this instance (default [])
+  -h, --help                               Help for "stackit secrets-manager instance update"
+      --kms-key-id string                  ID of the KMS key to use for encryption
+      --kms-key-version int                Version of the KMS key
+      --kms-keyring-id string              ID of the KMS key ring
+      --kms-service-account-email string   Service account email for KMS access
 ```
 
 ### Options inherited from parent commands