Revise https://etcd.io/docs/v3.5/tutorials/how-to-create-lease/

**Pair up for this one!**

This issue was created in preparation for the Contributor Summit docs sprint.

File:https://github.com/etcd-io/website/blob/main/content/en/docs/v3.6/tutorials/how-to-create-lease.md

Per https://github.com/etcd-io/website/issues/765, do the following:

- Retitle file "Granting and revoking leases"
- Add prerequisites (etcdctl and a currently running etcd cluster are required)
- Define all variables and flags used in the examples in a bulleted list (in this case, `--endpoints, `put`, `get`, `grant`, `revoke` `value` `--lease`, `keep-alive`)
- Link to https://etcd.io/docs/v3.5/dev-guide/interacting_v3/#grant-leases so that people can learn more about leases if they need to

When done, the document should have the following sub-sections (## H2 headings):

- Pre-requisites
- Grant a lease
- Revoke a lease (**new section, code sample is in https://etcd.io/docs/v3.5/dev-guide/interacting_v3/#revoke-leases**)