Doesn't seem to do anything at all?

**Describe the bug**
I've installed the extension and signed in to github, but nothing has changed in VS code. There's no sidebar icon like in the screenshots, and since there's no documentation, I have no idea what to do now.

**To Reproduce**
Steps to reproduce the behavior:
1. Install github actions extension
2. ???

**Expected behavior**
I actually have no idea what to expect. Is this supposed to let me run and debug github actions locally? I have no idea because there's no documentation. Selecting my workflow yml files just views them same as it always has.

I would at least expect to see something similar to in your screenshots, but it looks no different with it installed or not.

**Extension Version**
`v0.27.2`

No source files or tests are named. Start by reviewing the extension's installation and activation behavior, then document what the sidebar icon and workflow files should do; done means a new user can follow the installation steps and understand the extension's expected behavior.

Written by the indexing model from the issue text.