Document usage and upgrade of dotnetcore-sdk for CCM

[mkevenaar]

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When upgrading CCM to the latest edition, the package dotnetcore-sdk was added as a dependency for chocolatey-management-database

For other dependencies the upgrade page states what versions are "safe" to upgrade to, basically only minor and patches are supported.

I think it would be wise to document this for the dotnetcore-sdk package as well.

[pauby]

To be clear on what you're looking for, would you be able to raise a PR for this?