DOC-4093 HGET/HSET command code samples (redis#330)

* DOC-4093 added hash examples

* DOC-4093 dotnet format changes

tests/Doc/CmdsHashExample.cs

@@ -0,0 +1,87 @@
+// EXAMPLE: cmds_hash
+// HIDE_START
+
+using NRedisStack.Tests;
+using StackExchange.Redis;
+
+// HIDE_END
+
+// REMOVE_START
+namespace Doc;
+[Collection("DocsTests")]
+// REMOVE_END
+
+// HIDE_START
+public class CmdsHashExample
+{
+
+    [SkipIfRedis(Is.OSSCluster)]
+    public void run()
+    {
+        var muxer = ConnectionMultiplexer.Connect("localhost:6379");
+        var db = muxer.GetDatabase();
+        //REMOVE_START
+        // Clear any keys here before using them in tests.
+        db.KeyDelete("myhash");
+        //REMOVE_END
+        // HIDE_END
+
+
+        // STEP_START hget
+        bool res1 = db.HashSet("myhash", "field1", "foo");
+
+        RedisValue res2 = db.HashGet("myhash", "field1");
+        Console.WriteLine(res2);    // >>> foo
+
+        RedisValue res3 = db.HashGet("myhash", "field2");
+        Console.WriteLine(res3);    // >>> Null
+        // STEP_END
+
+        // Tests for 'hget' step.
+        // REMOVE_START
+        Assert.True(res1);
+        Assert.Equal("foo", res2);
+        Assert.Equal(RedisValue.Null, res3);
+        db.KeyDelete("myhash");
+        // REMOVE_END
+
+        // STEP_START hset
+        bool res4 = db.HashSet("myhash", "field1", "Hello");
+        RedisValue res5 = db.HashGet("myhash", "field1");
+        Console.WriteLine(res5);    // >>> Hello
+
+        db.HashSet(
+            "myhash",
+            new HashEntry[] {
+                new HashEntry("field2", "Hi"),
+                new HashEntry("field3", "World")
+            }
+        );
+
+        RedisValue res6 = db.HashGet("myhash", "field2");
+        Console.WriteLine(res6);    // >>> Hi
+
+        RedisValue res7 = db.HashGet("myhash", "field3");
+        Console.WriteLine(res7);    // >>> World
+
+        HashEntry[] res8 = db.HashGetAll("myhash");
+        Console.WriteLine($"{string.Join(", ", res8.Select(h => $"{h.Name}: {h.Value}"))}");
+        // >>> field1: Hello, field2: Hi, field3: World
+        // STEP_END
+
+        // Tests for 'hset' step.
+        // REMOVE_START
+        Assert.True(res4);
+        Assert.Equal("Hello", res5);
+        Assert.Equal("Hi", res6);
+        Assert.Equal("World", res7);
+        Assert.Equal(
+            "field1: Hello, field2: Hi, field3: World",
+            string.Join(", ", res8.Select(h => $"{h.Name}: {h.Value}"))
+        );
+        // REMOVE_END
+        // HIDE_START
+    }
+}
+// HIDE_END
+