Added some javadoc in PlaceholdersManager

src/main/java/world/bentobox/bentobox/managers/PlaceholdersManager.java

@@ -5,6 +5,11 @@
 import world.bentobox.bentobox.api.placeholders.PlaceholderReplacer;
 import world.bentobox.bentobox.hooks.PlaceholderAPIHook;
 
+/**
+ * Manages placeholder integration.
+ *
+ * @author Poslovitch
+ */
 public class PlaceholdersManager {
 
     private BentoBox plugin;
@@ -13,6 +18,11 @@ public PlaceholdersManager(BentoBox plugin) {
         this.plugin = plugin;
     }
 
+    /**
+     * Registers the placeholder on the behalf on BentoBox.
+     * @param placeholder the placeholder to register. It will be appended with {@code "bentobox_"} by the placeholder plugin.
+     * @param replacer the expression that will return a {@code String} when executed, which will replace the placeholder.
+     */
     public void registerPlaceholder(String placeholder, PlaceholderReplacer replacer) {
         // Register it in PlaceholderAPI
         plugin.getHooks().getHook("PlaceholderAPI").ifPresent(hook -> {
@@ -21,6 +31,11 @@ public void registerPlaceholder(String placeholder, PlaceholderReplacer replacer
         });
     }
 
+    /**
+     * Registers the placeholder on the behalf of the specified addon.
+     * @param placeholder the placeholder to register. It will be appended with the addon's name by the placeholder plugin.
+     * @param replacer the expression that will return a {@code String} when executed, which will replace the placeholder.
+     */
     public void registerPlaceholder(Addon addon, String placeholder, PlaceholderReplacer replacer) {
         if (addon == null) {
             registerPlaceholder(placeholder, replacer);