add instructions

README.md

@@ -1,2 +1,29 @@
 # Backend
 Vencord API
+
+## Hosting
+The API has a Docker Compose configuration, so software-wise you shouldn't need much more than just Docker.
+Docker is the official way of hosting the backend, and other setups (whilst technically supported) will be
+up to you to manage.
+
+1. Clone the repository
+2. Copy `.env.example` to `.env`
+3. Configure as necessary
+  - Port and host are irrelevant since it's running in a container, but you can change them if you wish.
+  - `REDIS_URI` should be changed to `redis:6379`.
+  - `ROOT_REDIRECT` should be changed to whatever you want the `/` of the API to be set to a different site,
+    like your own personal homepage.
+  - `DISCORD_*` should be configured with your Discord application.
+  - `PEPPER_*` should be unique values. These provide extra anonymity and make it more difficult to get user
+    info.
+  - `SIZE_LIMIT` is up to you, but should usually be left as default. This is for the settings sync and how
+    much data a user can store.
+4. Create a `docker-compose.override.yml` that maps your ports, like so:
+   ```yaml
+   services:
+     backend:
+       ports:
+         - HOST_PORT:8080
+   ```
+5. `docker compose up -d`
+6. Configure a reverse proxy to serve the backend as `/v1/` on whatever domain you please.