Add module descriptions in JavaDoc format

Descriptions were added for two modules - SnowGolemShearDropsPumpkinModule and RandomColorJebSheepShearModule. These comments in JavaDoc format will help in better understanding the functionality of these modules by giving an insight into their purpose and behavior.

src/main/java/org/purpurmc/purpurextras/modules/RandomColorJebSheepShearModule.java

@@ -14,6 +14,9 @@
 import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * If enabled causes sheep named jeb_ to drop random colors of wool
+ */
 public class RandomColorJebSheepShearModule implements PurpurExtrasModule, Listener {
 
     private final List<Material> coloredWool = new ArrayList<>();

src/main/java/org/purpurmc/purpurextras/modules/SnowGolemShearDropsPumpkinModule.java

@@ -10,6 +10,9 @@
 
 import java.util.ArrayList;
 
+/**
+ * A module that disables the dropping of pumpkins when a Snow Golem is sheared.
+ */
 public class SnowGolemShearDropsPumpkinModule implements PurpurExtrasModule, Listener {
 
     @Override