Add label descriptions (#3662)

* Add label descriptions

* Add default descriptions to label template

options/label/Default

@@ -1,7 +1,7 @@
-#ee0701 bug
-#cccccc duplicate
-#84b6eb enhancement
-#128a0c help wanted
-#e6e6e6 invalid
-#cc317c question
-#ffffff wontfix
+#ee0701 bug ; Something is not working
+#cccccc duplicate ; This issue or pull request already exists
+#84b6eb enhancement ; New feature
+#128a0c help wanted ; Need some help
+#e6e6e6 invalid ; Something is wrong
+#cc317c question ; More information is needed
+#ffffff wontfix ; This won't be fixed