Rewrites the Redis quick start example (examples/scripts/redis.ts) to use
the popular npm:redis client (node-redis) instead of jsr:@iuioiua/redis.

This makes the quick start consistent with the companion caching tutorial,
which already uses node-redis, and addresses the confusion reported in #1676:

• The connection now uses createClient with an explicit socket.host and
  port, so it's clear where a remote host goes (the original only showed a
  port).
• Reading and writing use the high-level set/get methods rather than raw
  sendCommand, which is what tripped up the reporter.
• A sendCommand example remains for commands without a dedicated method
  (such as RedisJSON's JSON.SET), showing each argument as a separate array
  element.

Type-checks against node-redis 4.7.1 and passes deno fmt.

Closes #1676