[doc] Rename ti.struct_class to ti.dataclass (#5706)

docs/lang/articles/advanced/odop.md

@@ -278,20 +278,20 @@ print(a.num())  # 6
 print(b.num())  # 7
 ```
 
-## Python classes as Taichi struct types
+## Taichi dataclasses
 
 Taichi provides custom [struct types](../type/type.md#compound-types) for developers to associate pieces of data together. However, it is often convenient to have:
   1. A Python representation of the struct type which is more object oriented.
   2. Functions associated with a struct type. (C++ style structs)
 
 
-To achieve these two points, developers can use the `@ti.struct_class` decorator on a Python class.  This is heavily inspired by the Python [dataclass](https://docs.python.org/3/library/dataclasses.html) feature, which uses class fields with annotations to create data types.
+To achieve these two points, developers can use the `@ti.dataclass` decorator on a Python class.  This is heavily inspired by the Python [dataclass](https://docs.python.org/3/library/dataclasses.html) feature, which uses class fields with annotations to create data types.
 
 ### Creating a struct from a Python class
 Here is an example of how we could create a Taichi struct type from a Python class:
 
 ```python
-@ti.struct_class
+@ti.dataclass
 class Sphere:
     center: vec3
     radius: ti.f32
@@ -301,7 +301,7 @@ This will create the *exact* same type as doing:
 ```python
 Sphere = ti.types.struct(center=vec3, radius=ti.f32)
 ```
-Using the `@ti.struct_class` decorator will convert the annotated fields in the Python class to members in the resulting struct type.  In both of the above examples you would create a field of the struct the same way.
+Using the `@ti.dataclass` decorator will convert the annotated fields in the Python class to members in the resulting struct type.  In both of the above examples you would create a field of the struct the same way.
 
 ```python
 sphere_field = Sphere.field(shape=(n,))
@@ -311,7 +311,7 @@ sphere_field = Sphere.field(shape=(n,))
 Python classes can have functions attached to them, as can Taichi struct types.  Building from the above example, here is how one would add functions to the struct.
 
 ```python
-@ti.struct_class
+@ti.dataclass
 class Sphere:
     center: vec3
     radius: ti.f32
@@ -341,9 +341,9 @@ def get_area() -> ti.f32:
 get_area() # 201.062...
 ```
 
-### Notes on struct classes
-- Inheritance of struct classes is not implemented.
-- While functions attached to a struct with the `@ti.struct_class` decorator is convenient and encouraged, it is actually possible to associate a function to structs with the older method of defining structs.  As mentioned above, the two methods for defining a struct type are identical in their output.  To do this, use the `__struct_methods` argument with the `ti.types.struct` call:
+### Notes
+- Inheritance of Taichi dataclasses is not implemented.
+- While functions attached to a struct with the `@ti.dataclass` decorator is convenient and encouraged, it is actually possible to associate a function to structs with the older method of defining structs.  As mentioned above, the two methods for defining a struct type are identical in their output.  To do this, use the `__struct_methods` argument with the `ti.types.struct` call:
 
 ```python
 @ti.func