Create dev container feature for aspire

[davidfowl]

With the codespaces work, we should complete the loop on this feature, we should provide a https://code.visualstudio.com/docs/devcontainers/containers#_dev-container-features that makes it easier to setup a new codespace/devcontainer with aspire

[danmoseley]

devcontainers/features#1257

[mitchdenny]

So I think the way we make this work to make an overall smooth acquisition experience is that we create the feature as described above, but we also have a template repo with it all pre-configured (to make getting started easier). So we would end up with the following:

https://github.com/dotnet/aspire-devcontainer (for released bits)
https://github.com/dotnet/aspire-devcontainer-nightly (includes a nuget that points to our nightly builds)
https://github.com/dotnet/aspire-devcontainer-feature

[mitchdenny]

The feature will probably just do things like install the specific version of the templates - and possibly precache some of the packages to improve the experience.

[danmoseley]

Agreed, and I will work on moving there tonight.

[danmoseley]

dotnet/aspire-devcontainer-feature#2 but either I make it use 9.0 or I wait until 9.1 releases to merge it.