[ci skip] Add token instructions to README

README.md

@@ -19,8 +19,13 @@ To start off, clone the repository into your desired directory:
 git clone https://github.com/BrackeysBot/Hammer.git
 ```
 
-### Setting up for Docker compose
-Two directories are required to exist for Docker compose to mount as container volumes.
+### Setting things up
+The bot's token is passed to the container using the `DISCORD_TOKEN` environment variable. Create a file named `.env`, and add the following line:
+```
+DISCORD_TOKEN=your_token_here
+```
+
+Two directories are required to exist for Docker compose to mount as container volumes, `data` and `logs`:
 ```bash
 mkdir data
 mkdir logs