Rename Show to Debug, String to Display
Update reference.md:
- derive() no longer supports Zero trait
- derive() now supports Copy trait
@@ -2356,8 +2356,8 @@ Supported traits for `derive` are:
* `FromPrimitive`, to create an instance from a numeric primitive.
* `Hash`, to iterate over the bytes in a data type.
* `Rand`, to create a random instance of a data type.
-* `Show`, to format a value using the `{}` formatter.
-* `Zero`, to create a zero instance of a numeric data type.
+* `Debug`, to format a value using the `{:?}` formatter.
+* `Copy`, for "Plain Old Data" types which can be copied by simply moving bits.
### Compiler Features
