Fix #2537 add VSCodium

[GitMensch]

and minor change in the text to VisualStudioCode to distinguish its MIT-licensed "core" with the provided un-free binaries (+telemetry/tracking) between the option added.

As the reference was not 100% clean - this fixes git-for-windows/git#2537.

[dscho]

@GitMensch Hmm. Bad news. VS Codium, despite its good intentions, seems to violate Visual Studio's Marketplace terms:

section 1.b, sentence 2

Marketplace Offerings are intended for use only with Visual Studio Products and Services and you may only install and use Marketplace Offerings with Visual Studio Products and Services.

We might have to kick VS Codium out of Git for Windows' installer unless that issue is resolved.

[GitMensch]

See the according documentation at https://github.com/VSCodium/vscodium/blob/master/DOCS.md#extensions-marketplace and issues about this on the vscode repo like microsoft/vscode#1557.
Further on the vscode repo (licensed under MIT) uses the marketplace extension api (the code for this is MIT-licensed and this part seems to be covered under a different point) so if something at all is "questionable" is the URL address to the marketplace in the project.json, correct?

Note: there's work in progress in vscodium to move from the MS marketplace to the Open VSX Repository, so maybe leaving this "open" until then?

[dscho]

I just need to know that this is being addressed.

It was very concerning to me to see a blatant violation of terms by a project that wants to claim high moral ground. That's just not right.

[GitMensch]

Just as an update: if the user doesn't manually switch to any other extension provider then the default (with each vscodium installation/update) is the Open VSX Registry, not the ms-marketplace.

[dscho]

That's good, but it should not even offer the marketplace, as it is a violation of terms.

[GitMensch]

It doesn't offer the MS marketplace at all, but should not prevent people from adjusting their local vscode files to point to a different extension provider.