[compose] Add WAYLAND_DISPLAY variable

docs/getting-started/docker/composition.md

@@ -52,6 +52,7 @@ Some variables might need to be tuned to match your setup such as the `TZ`, `XDG
 | `TZ`                          | `America/Montreal`                                 | :fontawesome-brands-linux:{ .lg title="Linux" } :fontawesome-brands-raspberry-pi:{ .lg title="Raspberry Pi" } :fontawesome-brands-apple:{ .lg title="Mac OS" } :fontawesome-brands-windows:{ .lg title="Windows WSL2" } | Timezone to set in the container       |
 | `VERSION`                     | `alpha`                                            | :fontawesome-brands-linux:{ .lg title="Linux" } :fontawesome-brands-raspberry-pi:{ .lg title="Raspberry Pi" } :fontawesome-brands-apple:{ .lg title="Mac OS" } :fontawesome-brands-windows:{ .lg title="Windows WSL2" } | Container image tag to pull            |
 | `VIDEO_GID`                   | `44`                                               | :fontawesome-brands-linux:{ .lg title="Linux" } :fontawesome-brands-raspberry-pi:{ .lg title="Raspberry Pi" }                                                                                                           | `video` group ID                       |
+| `WAYLAND_DISPLAY`             | `wayland-0`                                        | :fontawesome-brands-linux:{ .lg title="Linux" } :fontawesome-brands-raspberry-pi:{ .lg title="Raspberry Pi" }                                                                                                           | Compositor used by Wayland             |
 | `XDG_RUNTIME_DIR`             | `/run/user/1000`                                   | :fontawesome-brands-linux:{ .lg title="Linux" } :fontawesome-brands-raspberry-pi:{ .lg title="Raspberry Pi" } :fontawesome-brands-windows:{ .lg title="Windows WSL2" }                                                  | Path to XDG runtime directory          |
 
 !!! bug "Do not change `OVOS_USER` or `HIVEMIND_USER`"