start on 1.13 migrations

Author: kashike

migrations/1.12-to-1.13.md

@@ -0,0 +1,14 @@
+* Class changes
+
+| Old Name (1.12)                | New Name (1.13)                    |
+|--------------------------------|------------------------------------|
+| client.settings.GameSettings   | client.GameSettings                |
+| item.crafting.ShapedRecipes    | item.crafting.ShapedRecipe         |
+| item.crafting.ShapelessRecipes | item.crafting.ShapelessRecipe      |
+| util.ChatAllowedCharacters     | util.SharedConstants               |
+| util.MouseHelper               | client.MouseHelper                 |
+| world.DimensionType            | world.dimension.DimensionType      |
+| world.WorldProvider            | world.dimension.Dimension          |
+| world.WorldProviderEnd         | world.dimension.EndDimension       |
+| world.WorldProviderNether      | world.dimension.NetherDimension    |
+| world.WorldProviderOverworld   | world.dimension.OverworldDimension |