Clarify monument completion info

Author: Plastix

src/modules/gamemode_dtm.haml

@@ -20,4 +20,4 @@
                             </destroyable>
                         </destroyables>
 
-                    Completion specifies how much of the material inside of the region must be removed for it to count as destroyed. This means that if the destroyable is 50% obsidian, and 50% wood and completion is set to 100%; then all the obsidian must be removed. The plugin won't care 1&cent; about the wood.
+                    Completion specifies how much of the material(s) inside of the monument region must be removed for it to count as destroyed. For example, if the monument is obsidian and completion is set to 100% then all the obsidian must be removed in order for the monument to count as destroyed.