chore: add a few missing return javadoc comments

chat/src/main/java/com/github/twitch4j/chat/TwitchChat.java

@@ -146,7 +146,8 @@ public class TwitchChat implements AutoCloseable {
      * @param chatCredential Chat Credential
      * @param commandPrefixes Command Prefixes
      * @param chatQueueSize Chat Queue Size
-     * @param chatRateLimit Bandwidth / Bucket
+     * @param chatRateLimit Bandwidth / Bucket for chat
+     * @param whisperRateLimit Bandwidth / Buckets for whispers
      * @param taskExecutor ScheduledThreadPoolExecutor
      * @param chatQueueTimeout Timeout to wait for events in Chat Queue
      */

common/src/main/java/com/github/twitch4j/common/util/CollectionUtils.java

@@ -9,6 +9,7 @@ public class CollectionUtils {
     /**
      * Assigns elements of the given iterable to chunks not exceeding the desired size
      *
+     * @param <T> type of the iterable
      * @param iterable the source of elements to be assigned to a chunk
      * @param size the maximum size of each chunk
      * @return a list of the chunks, or an empty list if the iterable yielded no elements

pubsub/src/main/java/com/github/twitch4j/pubsub/domain/SubscriptionData.java

@@ -89,20 +89,26 @@ public class SubscriptionData {
 
     /**
      * The id of the user that received the subscription
+     *
+     * @return the recipient id
      */
     public String getRecipientId() {
         return this.recipientId != null ? this.recipientId : this.userId;
     }
 
     /**
      * The login name of the user that received the subscription
+     *
+     * @return the recipient name
      */
     public String getRecipientUserName() {
         return this.recipientUserName != null ? this.recipientUserName : this.userName;
     }
 
     /**
      * The display name of the user that received the subscription
+     *
+     * @return the recipient display name
      */
     public String getRecipientDisplayName() {
         return this.recipientDisplayName != null ? this.recipientDisplayName : this.displayName;

twitch4j/src/main/java/com/github/twitch4j/events/ChannelChangeGameEvent.java

@@ -25,6 +25,8 @@ public class ChannelChangeGameEvent extends TwitchEvent {
 
     /**
      * The new stream gameId
+     *
+     * @return id of the game
      */
     public String getGameId() {
         return stream.getGameId();

twitch4j/src/main/java/com/github/twitch4j/events/ChannelChangeTitleEvent.java

@@ -25,6 +25,8 @@ public class ChannelChangeTitleEvent extends TwitchEvent {
 
     /**
      * The new stream title
+     *
+     * @return current title for the stream
      */
     public String getTitle() {
         return stream.getTitle();