docs: add initial but kinda bad & unfinished docs

README.md

@@ -1,5 +1,17 @@
 # matrix-sip-bridge
 A bridge between [Matrix](https://matrix.org/) and VoIP via [SIP](https://en.wikipedia.org/wiki/Session_Initiation_Protocol) to answer (and in future make) phone calls from Matrix.
 
-| :exclamation: Documentation will follow shortly |
-|:--|
+## Please be aware, that this is considered **early stage software**
+There may or may not be a lot of bugs and breaking changes. 
+But *especially* because of this, you will be able to influence how this project continues to develop.
+
+Feel free to [file issues](https://github.com/IndeedNotJames/matrix-sip-bridge/issues/new), ask questions, provide feedback, [hang out in the official matrix room](#matrix-room) or contribute some code - or whatever! 😊
+
+## Documentation
+Documentation can be found in [`./docs`](https://github.com/IndeedNotJames/matrix-sip-bridge/tree/main/docs)
+If you'd like to improve those, feel free to file a pull request or [let us know](#matrix-room) where some things were unclear to you.   
+
+## Matrix Room
+Feel free to ask questions, provide feedback or just hang out in the official Matrix room:
+
+[#matrix-sip-bridge:indeednotjames.com](https://matrix.to/#/#matrix-sip-bridge:indeednotjames.com)

docs/README.md

@@ -0,0 +1,59 @@
+# matrix-sip-bridge documentation
+
+The current documentation is somewhat suboptimal and there are many things to improve.
+If you need any help, feel free to ask any questions in the [matrix room](https://github.com/IndeedNotJames/matrix-sip-bridge/blob/main/README.md#matrix-room)
+
+## Install
+As of now, the installation is pretty Docker centric, but it should be fine to just use `npm install`/`yarn install` with a *systemd* or *openrc* service.
+It will improve in the future™
+
+### Docker
+How to install Docker is likely out of the scope of this document. Follow the [official Docker install](https://docs.docker.com/engine/install/) steps if you haven't already. Podman should in theory work just fine too.
+
+The official container image is available both at https://github.com/indeednotjames/matrix-sip-bridge/pkgs/container/matrix-sip-bridge and https://hub.docker.com/r/indeednotjames/matrix-sip-bridge
+
+#### Supported Docker tags
+* `latest` is the latest stable release
+* `x.y.z` is a specific `x.y.z` release (e.g. `:0.1.0`)
+* `x.y` is a specific `x.y.*` release (e.g. `:0.1` would point `:0.1.0` or `:0.1.1`)
+* `edge` is always the latest commit (unstable, "living on the edge")
+* `sha-*` allows you to run a specific commit
+
+At the time of writing, you have to use the `:edge` that, because there hasn't been a release yet:
+- `ghcr.io/indeednotjames/matrix-sip-bridge:edge` or
+- `indeednotjames/matrix-sip-bridge:edge` (`docker.io/indeednotjames/matrix-sip-bridge:edge`)
+
+**An example [`docker-compose.yml`](https://github.com/IndeedNotJames/matrix-sip-bridge/blob/main/docker-compose.yml) is available to use at the projects root.**
+
+Alternatively, you can build a huge `docker run` command like so:
+See [Configure](#configure) for all required options.
+
+```bash
+❯ docker run \
+    --restart=always \
+    --name=matrix-sip-bridge \
+    --env="MX_HOMESERVER=https://homeserver.example" \
+    --env="MX_ACCESSTOKEN=See 'Configure' below" \
+    --env="MX_USERID=@localpart:homeserver.example" \
+    --env="MX_ROOMID=!roomId:homeserver.example" \
+    --env="SIP_SERVER=wss://sip.sipgate.de" \
+    --env="SIP_URI=sip:[email protected]" \
+    --env="SIP_USER=your userAddress" \
+    --env="SIP_PASSWORD=your sip user password" \
+    ghcr.io/indeednotjames/matrix-sip-bridge:edge
+```
+
+## Configure
+As of now, everything gets configured via environment variables and there is no persistent data volume needed.
+However, there is a pretty high chance this will later down the road.
+
+All those environment variables are listed in the [`.env-example` file](https://github.com/IndeedNotJames/matrix-sip-bridge/blob/main/.env-example).
+In detail explanations will follow eventually.
+
+### SIP
+Your SIP server requires websocket support for now.
+
+For example *sipgate.de* provides `wss://sip.sipgate.de` for you to use.
+
+### Obtaining an access token
+Follow https://t2bot.io/docs/access_tokens/ for way to get your bot account's access token via Element.