example: Use a Redis cacheHandler w/o dependencies (#95346)
Verify locally:
- Copy the example to a local directory
- Install deps
- docker compose up -d
- npm run build && npm run start
- navigate to localhost:3000/cet (or gmt)
- open the Redis view (link in localhost:3000/cet)
- revalidate data on /cet or /gmt
- verify it on the Redis view
I had to update the app to async params, updateTag, and write the
handler in such a way that it solved:
```
⨯ TypeError: p.segmentData.get is not a function
at ignore-listed frames
⨯ Error: failed to pipe response
```
Also adding docs edits with this caveat.
An agent review, and cross checking with a community implementation,
surfaced, that we had to read tags from
`data.headers['x-next-cache-tags']`. This agent review added a few
comments, I think they are useful, but can cut down if needed.
Last but not least, had to update the Time API endpoint (former no
longer worked).
