chore: update README.md

Author: actions-user

README.md

@@ -177,7 +177,7 @@ Available targets:
 | <a name="input_label_order"></a> [label\_order](#input\_label\_order) | The order in which the labels (ID elements) appear in the `id`.<br/>Defaults to ["namespace", "environment", "stage", "name", "attributes"].<br/>You can omit any of the 6 labels ("tenant" is the 6th), but at least one must be present. | `list(string)` | `null` | no |
 | <a name="input_label_value_case"></a> [label\_value\_case](#input\_label\_value\_case) | Controls the letter case of ID elements (labels) as included in `id`,<br/>set as tag values, and output by this module individually.<br/>Does not affect values of tags passed in via the `tags` input.<br/>Possible values: `lower`, `title`, `upper` and `none` (no transformation).<br/>Set this to `title` and set `delimiter` to `""` to yield Pascal Case IDs.<br/>Default value: `lower`. | `string` | `null` | no |
 | <a name="input_labels_as_tags"></a> [labels\_as\_tags](#input\_labels\_as\_tags) | Set of labels (ID elements) to include as tags in the `tags` output.<br/>Default is to include all labels.<br/>Tags with empty values will not be included in the `tags` output.<br/>Set to `[]` to suppress all generated tags.<br/>**Notes:**<br/>  The value of the `name` tag, if included, will be the `id`, not the `name`.<br/>  Unlike other `null-label` inputs, the initial setting of `labels_as_tags` cannot be<br/>  changed in later chained modules. Attempts to change it will be silently ignored. | `set(string)` | <pre>[<br/>  "default"<br/>]</pre> | no |
-| <a name="input_master_password"></a> [master\_password](#input\_master\_password) | (Required unless a snapshot\_identifier is provided) Password for the master DB user. Note that this may show up in logs, and it will be stored in the state file. Please refer to the DocumentDB Naming Constraints | `string` | `""` | no |
+| <a name="input_master_password"></a> [master\_password](#input\_master\_password) | (Required unless a snapshot\_identifier is provided) Password for the master DB user. Note that this may show up in logs, and it will be stored in the state file. Please refer to the DocumentDB Naming Constraints | `string` | `null` | no |
 | <a name="input_master_username"></a> [master\_username](#input\_master\_username) | (Required unless a snapshot\_identifier is provided) Username for the master DB user | `string` | `"admin1"` | no |
 | <a name="input_name"></a> [name](#input\_name) | ID element. Usually the component or solution name, e.g. 'app' or 'jenkins'.<br/>This is the only ID element not also included as a `tag`.<br/>The "name" tag is set to the full `id` string. There is no tag with the value of the `name` input. | `string` | `null` | no |
 | <a name="input_namespace"></a> [namespace](#input\_namespace) | ID element. Usually an abbreviation of your organization name, e.g. 'eg' or 'cp', to help ensure generated IDs are globally unique | `string` | `null` | no |