docs: Change Assign usage for Name

[eriklimakc]

Must be merged after #2185

PR Type

What kind of change does this PR introduce?

• Documentation content changes

What is the new behavior?

Changing .Assign(out var fe) usage for .Name(out var fe) in docs.

[eriklimakc]

In this second example below, should we leave it as is? If we change it to use .Name(out var slider) it would then be exactly the same as the first one.

uno.extensions/doc/Learn/Markup/DependencyPropertyBuilder.md

Lines 50 to 66 in 071fb9d

	```cs
	new Slider().Name(out var slider),
	new TextBlock()
	.Text(x => x
	.Source(slider)
	.Binding(() => slider.Value))
	```
	The second is that we can leverage the element name for our binding such as the following:
	```cs
	new TextBlock()
	.Text(x => x
	.Source("slider")
	.Binding(() => slider.Value)),
	new Slider().Name("slider")
	```

cc @Youssef1313 @dansiegel

[eriklimakc]

Should this be changed to .Name(out var myAnimatedRectangle)?

uno.extensions/doc/Learn/Markup/Storyboards.md

Lines 23 to 25 in 071fb9d

	```cs
	new Rectangle().Name("MyAnimatedRectangle");
	```

cc @Youssef1313 @dansiegel

[kazo0]

@Mergifyio backport release/stable/4.1

[mergify]

backport release/stable/4.1

✅ Backports have been created

• #2252 docs: Change Assign usage for Name (backport #2194) has been created for branch release/stable/4.1