vsce: add release steps and update feedback link

Created by: abeatrix

Closes https://github.com/sourcegraph/sourcegraph/issues/34742 https://github.com/sourcegraph/sourcegraph/issues/34822

This PR adds release steps for the extension and update the links for submitting feedback and feature request

Test plan

Docs and links update

App preview:

• Web
• Storybook

Check out the client app preview documentation to learn more.