[DOCS] Edit snapshot and restore summaries and descriptions

[lcawl]

Relates to #3226

This PR edits the snapshot and restore APIs (https://www.elastic.co/docs/api/doc/elasticsearch/group/endpoint-snapshot) based on information from https://www.elastic.co/guide/en/elasticsearch/reference/master/snapshot-restore-apis.html

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
snapshot.cleanup_repository	🟢	3/3	3/3
snapshot.clone	🟢	5/5	5/5
snapshot.create_repository	🔴	24/29	29/29
snapshot.create	🟢	28/28	28/28
snapshot.delete_repository	🟢	10/10	10/10
snapshot.delete	🔴	21/23	23/23
snapshot.get_repository	🔴	19/19	7/19
snapshot.get	🟢	13/13	13/13
snapshot.repository_verify_integrity	⚪	Missing test	Missing test
snapshot.restore	🟢	5/5	5/5
snapshot.status	🟢	2/2	2/2
snapshot.verify_repository	🟢	2/2	2/2

You can validate these APIs yourself by using the make validate target.

[karenzone]

Left some suggestions inline wrt moving the word "only" closer to the restriction it modifies. I know this was existing content, so you can decide. Otherwise, LGTM. 🚀

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
snapshot.cleanup_repository	🟢	3/3	3/3
snapshot.clone	🟢	5/5	5/5
snapshot.create_repository	🔴	24/29	29/29
snapshot.create	🟢	28/28	28/28
snapshot.delete_repository	🟢	10/10	10/10
snapshot.delete	🔴	21/23	23/23
snapshot.get_repository	🔴	19/19	7/19
snapshot.get	🟢	13/13	13/13
snapshot.repository_verify_integrity	⚪	Missing test	Missing test
snapshot.restore	🟢	5/5	5/5
snapshot.status	🟢	2/2	2/2
snapshot.verify_repository	🟢	2/2	2/2

You can validate these APIs yourself by using the make validate target.

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
snapshot.cleanup_repository	🟢	3/3	3/3
snapshot.clone	🟢	5/5	5/5
snapshot.create_repository	🔴	24/29	29/29
snapshot.create	🟢	28/28	28/28
snapshot.delete_repository	🟢	10/10	10/10
snapshot.delete	🔴	21/23	23/23
snapshot.get_repository	🔴	19/19	7/19
snapshot.get	🟢	13/13	13/13
snapshot.repository_verify_integrity	⚪	Missing test	Missing test
snapshot.restore	🟢	5/5	5/5
snapshot.status	🟢	2/2	2/2
snapshot.verify_repository	🟢	2/2	2/2

You can validate these APIs yourself by using the make validate target.

[github-actions]

Following you can find the validation results for the APIs you have changed.

API	Status	Request	Response
snapshot.cleanup_repository	🟢	3/3	3/3
snapshot.clone	🟢	5/5	5/5
snapshot.create_repository	🔴	24/29	29/29
snapshot.create	🟢	28/28	28/28
snapshot.delete_repository	🟢	10/10	10/10
snapshot.delete	🔴	21/23	23/23
snapshot.get_repository	🔴	19/19	7/19
snapshot.get	🟢	13/13	13/13
snapshot.repository_verify_integrity	⚪	Missing test	Missing test
snapshot.restore	🟢	5/5	5/5
snapshot.status	🟢	2/2	2/2
snapshot.verify_repository	🟢	2/2	2/2

You can validate these APIs yourself by using the make validate target.

[lcawl]

Left some suggestions inline wrt moving the word "only" closer to the restriction it modifies. I know this was existing content, so you can decide. Otherwise, LGTM. 🚀

Thanks for the edits! I've made added the suggested changes to the source files and regenerated the output files.