builder:Rule: add javadoc

builder/src/main/java/net/kemitix/checkstyle/ruleset/builder/Rule.java

@@ -11,7 +11,7 @@ import java.util.List;
 import java.util.Map;
 
 /**
- * .
+ * A single Checkstyle Check.
  *
  * @author Paul Campbell (paul.campbell@hubio.com)
  */
@@ -20,19 +20,43 @@ import java.util.Map;
 @Getter
 public class Rule {
 
+    /**
+     * The name of the rule's Check class.
+     */
     private String name;
 
+    /**
+     * The parent module.
+     */
     private RuleParent parent;
 
+    /**
+     * The first level the rule is enabled on.
+     */
     private RuleLevel level;
 
+    /**
+     * Whether the rule is enabled.
+     */
     private boolean enabled;
 
+    /**
+     * The source of the rule.
+     */
     private RuleSource source;
 
+    /**
+     * URI for full official documentation.
+     */
     private URI uri;
 
+    /**
+     * Configuration properties.
+     */
     private Map<String, String> properties = new HashMap<>();
 
+    /**
+     * Unofficial documentation.
+     */
     private List<String> body = new ArrayList<>();
 }