docs(simple-jwt): Optimised Javadoc.

Closes #18

simple-jwt-facade/src/main/java/cn/org/codecrafters/simplejwt/annotations/TokenEnum.java

@@ -25,7 +25,8 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * JwtEnum
+ * This annotation marks the enum field declared in payload class will be
+ * handled as basic data types in {@link TokenDataType}.
  *
  * @author Zihlu Wang
  */
@@ -33,8 +34,16 @@ import java.lang.annotation.Target;
 @Target({ElementType.FIELD})
 public @interface TokenEnum {
 
+    /**
+     * The name of the field of the base data corresponding to the
+     * enumeration data.
+     */
     String propertyName();
 
+    /**
+     * The attribute {@code dataType} specifies what base data type to treat
+     * this enum as.
+     */
     TokenDataType dataType();
 
 }

simple-jwt-facade/src/main/java/cn/org/codecrafters/simplejwt/constants/TokenDataType.java

@@ -20,21 +20,47 @@ package cn.org.codecrafters.simplejwt.constants;
 import lombok.Getter;
 
 /**
- * TokenDataType
+ * The base data types used to process enum data.
  *
  * @author Zihlu Wang
  */
 @Getter
 public enum TokenDataType {
 
+    /**
+     * Marks enumeration being processed as Boolean.
+     */
     BOOLEAN(Boolean.class),
+
+    /**
+     * Marks enumeration being processed as Double.
+     */
     DOUBLE(Long.class),
+
+    /**
+     * Marks enumeration being processed as Float.
+     */
     FLOAT(Float.class),
+
+    /**
+     * Marks enumeration being processed as Integer.
+     */
     INTEGER(Integer.class),
+
+    /**
+     * Marks enumeration being processed as Long.
+     */
     LONG(Long.class),
+
+    /**
+     * Marks enumeration being processed as String.
+     */
     STRING(String.class),
     ;
 
+    /**
+     * The mapped class to this mark.
+     */
     private final Class<?> mappedClass;
 
     TokenDataType(Class<?> mappedClass) {