docs: add run#bun option replacement

Author: JounQin

.changeset/silent-cows-drive.md

@@ -6,7 +6,8 @@ feat: make `is-bun-module` as optional peer dependency
 
 Technically this is a BREAKING CHANGE, but considering we just raise out v4 recently and this only affects `bun` users, `bun --bun eslint` even works without this dependency, so I'd consider this as a minor change.
 
-So for `bun` users, there are two options:
+So for `bun` users, there are three options:
 
 1. install `is-bun-module` dependency manually and use `bun: true` option
 2. run `eslint` with `bun --bun eslint` w/o `bun: true` option
+3. enable `run#bun` in [`bunfig.toml`](https://bun.sh/docs/runtime/bunfig#run-bun-auto-alias-node-to-bun)