Add swift devcontainer templates

[award999]

We can add Swift dev container templates to https://github.com/devcontainers/templates to make it simple to walk the user through setting up an dev container environment. Here is a great example: https://github.com/devcontainers/templates/blob/main/src/cpp/devcontainer-template.json

Here is an example of selecting C++ and then being prompted for linux variant:

SSWG has an example dev container setup that may be useful https://github.com/swift-server/swift-devcontainer-template

[adam-fowler]

The SSWG template is available already in VSCode. I'd be very happy for you to take it over or replace it with a swiftlang version

[award999]

@adam-fowler I wasn't thinking of a separate repo in swiftlang. If you checkout https://github.com/devcontainers/templates, if templates were contributed to this repo then it would become part of the UI for the dev containers extension. Some variables I was thinking include OS and version (ex. already swiftlang docker images for bookworm, jammy, etc.) and then the swift toolchain version

[adam-fowler]

The templates in the UI are submitted elsewhere. Can't remember where though. I'll have to go find it. If you go to create a devcontainer at the moment the SSWG swift template is available.

But it'd be good if we can get the swift template included in the official GH repo.

[award999]

Ya the UI ones are here I believe https://github.com/devcontainers/templates

[adam-fowler]

No there is a json file with a list of all the ones available in the UI. Can't remember where it is. I'll have to search for it.