Document some of our client classes

This is mostly aiming to give an overview rather than be anything
comprehensive (there's another 230+ undocumented classes to go :p), but
it's a start.

Mostly just an excuse for me to procrastinate working on the nasty bugs
though!

projects/forge/src/client/java/dan200/computercraft/client/model/TransformedBakedModel.java

@@ -18,6 +18,9 @@ import net.minecraftforge.client.model.data.ModelData;
 import javax.annotation.Nullable;
 import java.util.List;
 
+/**
+ * A {@link BakedModel} which applies a transformation matrix to its underlying quads.
+ */
 public class TransformedBakedModel extends BakedModelWrapper<BakedModel> {
     private final Transformation transformation;
     private final boolean invert;

projects/forge/src/client/java/dan200/computercraft/client/model/turtle/TurtleModel.java

@@ -15,6 +15,11 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+/**
+ * The custom model for turtle items, which renders tools and overlays as part of the model.
+ *
+ * @see TurtleModelParts
+ */
 public class TurtleModel extends BakedModelWrapper<BakedModel> {
     private final TurtleModelParts parts;
     private final Map<TurtleModelParts.Combination, List<BakedModel>> cachedModels = new HashMap<>();

projects/forge/src/client/java/dan200/computercraft/client/model/turtle/TurtleModelLoader.java

@@ -21,6 +21,12 @@ import net.minecraftforge.client.model.geometry.IUnbakedGeometry;
 
 import java.util.function.Function;
 
+/**
+ * A model loader for turtle item models.
+ * <p>
+ * This reads in the associated model file (typically {@code computercraft:block/turtle_xxx}) and wraps it in a
+ * {@link TurtleModel}.
+ */
 public final class TurtleModelLoader implements IGeometryLoader<TurtleModelLoader.Unbaked> {
     private static final ResourceLocation COLOUR_TURTLE_MODEL = new ResourceLocation(ComputerCraftAPI.MOD_ID, "block/turtle_colour");