docs: add a user's reported WSL2 setup to the getting-started guide (#960)

The getting-started guide records WSL2 as one user's reported working setup, not a supported platform.

README.md

@@ -420,7 +420,8 @@ seat, plugin, and release lifecycle actions remain agent-owned.
   longer supported. Node 26 and other versions are untested. On a Mac with Apple
   silicon, use Node.js 22: see the [compatibility history](docs/releases/v0.5.15.md#known-compatibility-limitation).
 - tmux
-- macOS or Linux. Native Windows is not supported yet, and WSL2 has not been tested
+- macOS or Linux. Native Windows is not supported yet. WSL2 isn't supported either;
+  one user's working setup is in the [getting-started guide](docs/reference/getting-started.md#wsl2-a-reported-working-setup)
 
 Optional:
 - herdr or cmux for terminal workspaces showing the agents together