Freshness pass on C++ docs

[AlexandraKemperMS]

Updating the C++ docs, for now the MinGW on Windows doc, might add more to this PR or do them as a separate PR.

[isidorn]

@AlexandraKemperMS there are some conflicts. Once you resolve those and tackle Rob's comments we can merge this in.

[gregvanl]

@AlexandraKemperMS How does your update align with #6276?
That community PR to update the installation to UCRT was approved but delayed for further engineering team testing.
Should PR #6276 be closed in favor of this refresh?

[AlexandraKemperMS]

@AlexandraKemperMS How does your update align with #6276? That community PR to update the installation to UCRT was approved but delayed for further engineering team testing. Should PR #6276 be closed in favor of this refresh?

Good point, we discussed with the engineering team and it should be fine to add, so I included it in this PR. UCRT is only shipped with Windows 10 or later, so I added an additional question to the troubleshooting section in case users run into issues. Also engineering team might take a look at these doc changes to verify, I shared the link with them.

[gregvanl]

@AlexandraKemperMS Let me know when you'd like this merged after the engineering team has a look.

[michelleangela]

⚠️ Do no merge yet until the extension is updated to look for the new UCRT path.

[AlexandraKemperMS]

@bobbrow @michelleangela we can wait on adding UCRT until the add the support in the extension, for now we can just release the freshness pass on these docs and add UCRT at a later time.