Add usage instructions

README.md

@@ -1,2 +1,18 @@
 # stockbot-buyvm
-Send alerts when [BuyVM](https://buyvm.net) has KVM slices in stock.
+Send alerts when [BuyVM](https://buyvm.net) has KVM slices in stock.
+
+## Usage
+1. Create a Discord Webhook and add it to `config.py`:
+```python
+DISCORD_WEBHOOK = '<discord webhook url>'
+```
+
+2. Build Docker container:
+```shell
+docker build -t stockbot-buyvm .
+```
+
+3. Run with a cronjob and optionally capture logs:
+```
+*/10 * * * * docker run --rm stockbot-buyvm >> /home/user/.local/logs/stockbot-buyvm.log 2>&1
+```