Add more info to DebuggerTypeProxyAttribute docs

[Youssef1313]

The API docs may link to the VS docs, or copy the relevant paragraph from it.

FYI @Sergio0694

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Issue Details

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The API docs may link to the VS docs, or copy the relevant paragraph from it.

FYI @Sergio0694

Author:	Youssef1313
Assignees:	-
Labels:	:watch: Not Triaged, Pri3, area-System.Diagnostics
Milestone:	-