Improves some descriptions, and fixes a nullability problem

src/main/java/net/knarcraft/knarlib/formatting/TranslatableTimeUnit.java

@@ -12,7 +12,7 @@ import org.jetbrains.annotations.NotNull;
 public enum TranslatableTimeUnit implements TranslatableMessage {
 
     /**
-     * The format for displaying the exact duration of a blacksmith's cool-down or delay
+     * The format for displaying the duation of something
      */
     DURATION_FORMAT,
 

src/main/java/net/knarcraft/knarlib/util/MaterialHelper.java

@@ -76,7 +76,7 @@ public final class MaterialHelper {
      *
      * @param materialString <p>The material string to parse</p>
      * @param logger         <p>The logger to use for logging parsing errors</p>
-     * @return <p>The materials defined by the material string, or an empty list if none were found</p>
+     * @return <p>The material defined by the material string, or null if not found</p>
      */
     public static @Nullable Material loadMaterialString(@NotNull String materialString, @NotNull Logger logger) {
         // Try to parse a material name

src/main/java/net/knarcraft/knarlib/util/UpdateChecker.java

@@ -37,7 +37,7 @@ public final class UpdateChecker {
      */
     public static void checkForUpdate(@NotNull Plugin plugin, @NotNull String apiResourceURL,
                                       @NotNull Supplier<String> getVersionSupplier,
-                                      @NotNull Consumer<String> setVersionMethod) {
+                                      @Nullable Consumer<String> setVersionMethod) {
         BukkitScheduler scheduler = plugin.getServer().getScheduler();
         scheduler.runTaskAsynchronously(plugin, () -> UpdateChecker.queryAPI(plugin, apiResourceURL, getVersionSupplier,
                 setVersionMethod));