add install instructions

README.md

@@ -1,3 +1,29 @@
 # vo-docker
 
-Vendetta Online in a Docker container
+[Vendetta Online](https://vendetta-online.com) in a Docker container
+
+Use case: Easy to install on systems that do not follow FHS (Filesystem Hierarchy Standard). Tested on NixOS. Guix users tell your experience.
+
+## Steps:
+1. Download client installer into `~/.vendetta`
+2. Clone the repo
+3. Build the container:
+```bash
+docker build -t vo .
+```
+4. Run `xhost +local:` to allow the container to use GUI.
+5. Run the container:
+```bash
+docker run -it --rm -e DISPLAY=$DISPLAY -e ALSA_CARD=sofhdadsp --device /dev/snd --device /dev/dri/card0 -v /tmp/.X11-unix/:/tmp/.X11-unix/ -v /home/user/.vendetta:/root/.vendetta vo
+```
+First time only: Install the client
+6. Play as usual.
+
+Next time onwards you just need to follow steps 6 and 7 (and 5 if you shut down your computer).
+
+## Known issues:
+1. You cannot write into `~/.vendetta` as unprivileged user on host machine. This is by design. You can always place plugins as root or use the container to do the same.
+
+## Possible issues:
+1. You might not get sound. To fix it, run `aplay -l` in the container and use whatever card it displays next time you run the container. Put the value in `ALSA_CARD`.
+2. If you have a dedicated GPU, you might consider passing `--gpus all` to the `docker run` command. It should use dGPU. I have not tested it.