DOCSP-40651 Add a new config shard type to the backup API doc (#276)

<!-- Add a description of your PR here (optional) -->

- [DOCSP-40651](https://jira.mongodb.org/browse/DOCSP-40651)
- STAGING
-
https://preview-mongodbkanchanamongodb.gatsbyjs.io/ops-manager/DOCSP-40651/reference/api/snapshots/get-all-snapshots-for-one-cluster/
-
https://preview-mongodbkanchanamongodb.gatsbyjs.io/ops-manager/DOCSP-40651/reference/api/snapshots/get-one-snapshot-for-one-cluster/
- [LATEST BUILD
LOG](https://workerpool-boxgs.mongodbstitch.com/pages/job.html?collName=queue&jobId=667c6c89ebce19f3145ddae4)

### Self-Review Checklist

- [ ]
[Define](https://wiki.corp.mongodb.com/display/DE/Taxonomy+tagging+instructions)
taxonomy
[values](https://wiki.corp.mongodb.com/display/DE/Docs+Taxonomy) at top
of page.
- [ ] Add genre facets (tutorial or reference), as in this [example
PR](10gen/cloud-docs#5042).
- [ ] Add programmingLanguage (if necessary).
- [ ] Add meta keywords (if necessary).
- [ ] Resolve any new warnings or errors in the build.
- [ ] Proofread for spelling and grammatical errors.
- [ ] Check staging for rendering issues.
- [ ] Confirm links are working.

Author: kanchana-mongodb

source/includes/api/list-tables/snapshot-rs-documents.rst

@@ -160,6 +160,7 @@
 
        - ``CONFIG_SERVER_REPLICA_SET``
        - ``REPLICA_SET``
+       - ``CONFIG_SHARD_REPLICA_SET``
 
    * - | ``missingShards``
        | ``.clusterName``
@@ -252,3 +253,4 @@
 
        - ``REPLICA_SET``
        - ``CONFIG_SERVER_REPLICA_SET``
+       - ``CONFIG_SHARD_REPLICA_SET``