docs(example): add example for setting TTL to "HSET Field" (#2027)

* Example for setting TTL to "HSET Field"

would make sense to have an example here.

* docs(example): add better httl examples

Author: ironnicko

examples/ttl.js

@@ -25,6 +25,14 @@ async function main() {
 
   await redis.persist("foo"); // Remove the existing timeout on key "foo"
   console.log(await redis.ttl("foo")); // -1
+
+  await redis.hset("hfoo", "hbar", "hfoobar");
+  // hexpire is available since Redis 7.4.0
+  await redis.hexpire("hfoo", 20, "FIELDS", 1, "hbar"); // Add TTL to hset field 
+  console.log(await redis.call("httl", "hfoo", "FIELDS", "1", "hbar")); // [ 20 ]
+  
+  await redis.hpexpire("hfoo", 10 * 1000, "FIELDS", 1, "hbar"); // unit is millisecond for hpexpire
+  console.log(await redis.call("httl", "hfoo", "FIELDS", "1", "hbar")); // [ 10 ]
 }
 
 main();