add instructions

Change-Id: I60c77f91cf62dfda39ccc0804b34bc1c1eff7998
Reviewed-on: https://git.clicks.codes/c/coded/EmojiUploader/+/284
Reviewed-by: Samuel Shuert <coded@clicks.codes>
Tested-by: Samuel Shuert <coded@clicks.codes>
diff --git a/README.md b/README.md
index 87ba27a..57af565 100644
--- a/README.md
+++ b/README.md
@@ -9,7 +9,7 @@
 To run:
 
 ```bash
-bun run index.ts
+TOKEN=DISCORD_TOKEN bun run index.ts
 ```
 
 This project was created using `bun init` in bun v1.0.13. [Bun](https://bun.sh) is a fast all-in-one JavaScript runtime.