feat: add vscode frontend feature for new amalthea

[olevski]

@rokroskar this is how we can use features to inject frontends into our sessions.

I am pretty sure this will work. I am not sure how to test this without fully publishing the feature though.

[rokroskar]

Nice, thanks!

[rokroskar]

this should be changed

[rokroskar]

Suggested change

	Installs vscode for running in Renku.
	Installs VSCode for running in Renku.

[rokroskar]

You can build an image locally by putting the content of this feature into a local .devcontainer directory and using the relative path in your devcontainer.json

[olevski]

Ah the problem is that the entrypoint field in the devcontainer feature spec does not get used in the image. I thought it will just override the entrypoint of the image that was built but it does not. It only gets executed when you start things with the devcontainer cli.