General improvements to the documentation

- Add documentation for all undocumented methods and enums.
 - Use @code, @link and @see where appropriate.
 - Fix spelling in a couple of cases.

src/main/java/dan200/computercraft/api/turtle/TurtleVerb.java

@@ -6,21 +6,24 @@
 
 package dan200.computercraft.api.turtle;
 
+import net.minecraft.util.EnumFacing;
+
 /**
- * An enum representing the two different actions that an ITurtleUpgrade of type
- * Tool may be called on to perform by a turtle.
- * @see ITurtleUpgrade
- * @see ITurtleUpgrade#useTool
+ * An enum representing the different actions that an {@link ITurtleUpgrade} of type Tool may be called on to perform by
+ * a turtle.
+ *
+ * @see ITurtleUpgrade#getType()
+ * @see ITurtleUpgrade#useTool(ITurtleAccess, TurtleSide, TurtleVerb, EnumFacing)
  */
 public enum TurtleVerb
 {
     /**
-     * The turtle called turtle.dig(), turtle.digUp() or turtle.digDown()
+     * The turtle called {@code turtle.dig()}, {@code turtle.digUp()} or {@code turtle.digDown()}
      */
     Dig,
-    
+
     /**
-     * The turtle called turtle.attack(), turtle.attackUp() or turtle.attackDown()
+     * The turtle called {@code turtle.attack()}, {@code turtle.attackUp()} or {@code turtle.attackDown()}
      */
     Attack,
 }