Fix commands in dev guide

Author: webpro

.github/DEVELOPMENT.md

@@ -24,8 +24,8 @@ gh repo fork webpro-nl/knip --clone
 cd knip
 bun install
 cd packages/knip
-npm run build
-npm run test
+bun run build
+bun run test
 ```
 
 Depending on the goals and the way you like to work, below are a few things that