JetBrains: Onboarding experience: Explaining users how to access the new Sourcegraph window

Created by: philipp-spiess

When a customer upgrades to the new JetBrains extension or installs it for the first time, they getting access to quite a few new features. How can we explaining to them what changed and how they can access the new Sourcegraph window?

On VSCode, we apparently show an after install pages that explains the extension (source: @muratsu). Do we want to replicate this for JetBrains?

Additionally there's the new notification that we've added when JetBrains is started and no external URL is configured yet that we can use to highlight new information.

cc @muratsu @jjinnii @ryankscott @vdavid

Expected outcome of this issue

• We discuss different options to improve the onboarding experience
• We decide on one option and move this to design/implementation stage