Add a rule for javadoc type

Author: shadromani

checkstyle.xml

@@ -333,6 +333,7 @@
             <property name="allowedAnnotations" value="Override, Test"/>
             <property name="tokens" value="METHOD_DEF, CTOR_DEF, ANNOTATION_FIELD_DEF, COMPACT_CTOR_DEF"/>
         </module>
+        <module name="JavadocType"/>
         <module name="MissingJavadocType">
             <property name="scope" value="protected"/>
             <property name="tokens"

src/main/java/com/maxmind/db/CacheKey.java

@@ -4,6 +4,8 @@
  * CacheKey is used as a key in the node cache. It contains the offset of the
  * node in the database file, the class of the data at that node, and the type
  * of the data at that node.
+ * 
+ * @param <T> the type of data stored at the node
  */
 public final class CacheKey<T> {
     private final int offset;

src/main/java/com/maxmind/db/DatabaseRecord.java

@@ -5,6 +5,8 @@
 /**
  * DatabaseRecord represents the data and metadata associated with a database
  * lookup.
+ *
+ * @param <T> the type of data stored at the node
  */
 public final class DatabaseRecord<T> {
     private final T data;