Creating a separate folder for runtime tests document

[fanyang-mono]

Currently, the documents for runtime tests are located at docs/workflow/testing/coreclr/. Since they are now shared by both CoreCLR and mono, it would be nice to create another folder called something like Runtime tests to store the documents of the nature of runtime tests, which could be shared by both mono and CoreCLR.

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[naricc]

@trylek This seems like documentation piece of your change moving the runtime tests themselves to a common directory.

Are there documents that need to be merged, or is it just a move? Like, parts of https://github.com/dotnet/runtime/blob/master/docs/workflow/testing/mono/testing.md might actually belong together with some of the exiting coreclr ones?

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Issue meta data

Issue content:	Currently, the documents for runtime tests are located at docs/workflow/testing/coreclr/. Since they are now shared by both CoreCLR and mono, it would be nice to create another folder called something like `Runtime tests` to store the documents of the nature of runtime tests, which could be shared by both mono and CoreCLR.
Issue author:	fanyang-mono
Assignees:	-
Milestone:	-

[ghost]

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Issue Details

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Currently, the documents for runtime tests are located at docs/workflow/testing/coreclr/. Since they are now shared by both CoreCLR and mono, it would be nice to create another folder called something like Runtime tests to store the documents of the nature of runtime tests, which could be shared by both mono and CoreCLR.

Author:	fanyang-mono
Assignees:	-
Labels:	area-Infrastructure, documentation
Milestone:	-