Update cmake language package in README

[hofbi]

VS Code is recommending that the language support extension bundled with the cmake-tools package has been updated (see microsoft/vscode-cmake-tools#2597). This PR updates the reference in the README from the old to the recommended cmake language extentions.

[bobbrow]

@hofbi Thanks for doing this for us. The bad news is that I reviewed your PR prior to reviewing feedback from the CMake Tools community about this change, and we're actually going to revert the dependency back to the old extension and push an update imminently as a result.

[hofbi]

Thanks for sharing.

I saw the old package got its last commit back in October 2019. Is there any expectation that this project will be further maintained?

[bobbrow]

I'm not sure what you mean. We updated it earlier this year.

[hofbi]

What I mean is the CMake package that I was actually updating with my PR. This CMake package has its last commit from October 2019.

[bobbrow]

Ah, I see. At this point we don't expect that extension to update again. We still recommend the newer extension over the older one and added a note in the README.md to this effect, but compatibility issues that our customers encountered out of the box were what ultimately drove us to roll back the change. Just because we bundle this extension doesn't mean you have to use it. You can uninstall the old extension and install the newer one instead. We're keeping the bundle because it's important to have at least some level of support for the language.