DOC-4494 SADD and SMEMBERS command examples (#3242)

* DOC-4494 added sadd example

* DOC-4494 sadd and smembers examples

* DOC-4494 better naming convention for result variables

---------

Co-authored-by: Nedyalko Dyakov <nedyalko.dyakov@gmail.com>

doctests/cmds_set_test.go

@@ -0,0 +1,102 @@
+// EXAMPLE: cmds_set
+// HIDE_START
+package example_commands_test
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/redis/go-redis/v9"
+)
+
+// HIDE_END
+
+func ExampleClient_sadd_cmd() {
+	ctx := context.Background()
+
+	rdb := redis.NewClient(&redis.Options{
+		Addr:     "localhost:6379",
+		Password: "", // no password docs
+		DB:       0,  // use default DB
+	})
+
+	// REMOVE_START
+	rdb.Del(ctx, "myset")
+	// REMOVE_END
+
+	// STEP_START sadd
+	sAddResult1, err := rdb.SAdd(ctx, "myset", "Hello").Result()
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(sAddResult1) // >>> 1
+
+	sAddResult2, err := rdb.SAdd(ctx, "myset", "World").Result()
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(sAddResult2) // >>> 1
+
+	sAddResult3, err := rdb.SAdd(ctx, "myset", "World").Result()
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(sAddResult3) // >>> 0
+
+	sMembersResult, err := rdb.SMembers(ctx, "myset").Result()
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(sMembersResult) // >>> [Hello World]
+	// STEP_END
+
+	// Output:
+	// 1
+	// 1
+	// 0
+	// [Hello World]
+}
+
+func ExampleClient_smembers_cmd() {
+	ctx := context.Background()
+
+	rdb := redis.NewClient(&redis.Options{
+		Addr:     "localhost:6379",
+		Password: "", // no password docs
+		DB:       0,  // use default DB
+	})
+
+	// REMOVE_START
+	rdb.Del(ctx, "myset")
+	// REMOVE_END
+
+	// STEP_START smembers
+	sAddResult, err := rdb.SAdd(ctx, "myset", "Hello", "World").Result()
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(sAddResult) // >>> 2
+
+	sMembersResult, err := rdb.SMembers(ctx, "myset").Result()
+
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println(sMembersResult) // >>> [Hello World]
+	// STEP_END
+
+	// Output:
+	// 2
+	// [Hello World]
+}