refactor: rename modules

Closes #75

identity-generator/README.md

@@ -0,0 +1,38 @@
+# Module `guid`
+
+## Introduction
+
+Module `guid` serves as a guid creator for other `JDevKit` modules. You can also use this module as a guid creator standards.
+
+We have already implemented `SnowflakeGuidCreator`, you can also implement a custom guid creations by implementing `com.onixbyte.identitygenerator.IdentityGenerator`.
+
+## Example usage
+
+### A UUID creator
+
+```java
+GuidCreator<UUID> uuidCreator = (GuidCreator<UUID>) UUID::randomUUID;
+```
+
+### A custom guid creator
+
+Assume that you need serial guid creator.
+
+```java
+@Component
+public class CustomGuidCreator implementes GuidCreator<String> {
+    
+    public final RedisTemplate<String, Long> serialRedisTemplate;
+    
+    @Autowired
+    public CustomGuidCreator(RedisTemplate<String, Long> serialRedisTemplate) {
+        this.serialRedisTemplate = serialRedisTemplate;
+    }
+    
+    @Override public String nextId() {
+        return "SOME_PREFIX" + serialRedisTemplate.opsForValue().get("some_serial_key");
+    }
+    
+}
+```
+