docs(caching.md): update redis example

[SlinkyPotato]

replace legacy https://github.com/dabroek/node-cache-manager-redis-store with forked https://github.com/node-cache-manager/node-cache-manager-redis-yet

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/docs.nestjs.com/blob/master/CONTRIBUTING.md

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Docs
• Other... Please describe:

What is the current behavior?

The original redis example of caching does not work with the latest version of cache manager. It looks like the package maintainers have abandoned the project node-cache-manager-redis-store.

Issue Number: N/A

What is the new behavior?

A new redis example is introduced that makes use of the forked repo node-manager-redis-yet.

Does this PR introduce a breaking change?

• Yes
• No

Other information

[Tony133]

There would already be a PR open here: #2703, waiting for it to be merged.

However, I hope it gets merged soon because it's the second PR being created related to this part of the redis-store, see also here: https://github.com/nestjs/docs.nestjs.com/pull /2778