Fix gui start, change docker container, add shell to start gui

README.md

@@ -26,13 +26,14 @@ docker build -f exwayz_test.dockerfile -t exwayz_test:latest .
 Run the container (example; adjust mounts and environment for your platform):
 
 ```powershell
-# Example (PowerShell+WSL on systems with X11 forwarding available)
+# Example (WSL on systems with X11 forwarding available)
 docker run -it --rm \
-    --env="DISPLAY=$env:DISPLAY" \
+    --env="DISPLAY=$DISPLAY" \
     --env="QT_X11_NO_MITSHM=1" \
     --volume="/tmp/.X11-unix:/tmp/.X11-unix:rw" \
     -v "${PWD}:/app" \
-    exwayz_test:latest
+    exwayz_test:latest \
+    /bin/bash
 ```
 
 On POSIX shells use `$DISPLAY` and `$(pwd)` as usual.