Fix README.md scenario example to use correct Wokwi format

- Add 'name' field to scenario example (required)
- Change 'sleep: 5000' to 'delay: 5s' with time units
- Add note about time units being required
- Matches correct Wokwi v0.19.1 scenario format

Co-authored-by: softhack007 <[email protected]>

Author: Copilot

test/wokwi/README.md

@@ -121,12 +121,13 @@ cd test/wokwi
 You can create your own scenario files in YAML format:
 
 ```yaml
+name: "Custom Test"
 version: 1
 timeout: 15000  # milliseconds
 
 steps:
   - name: "Description of step"
-    sleep: 5000  # wait 5 seconds
+    delay: 5s  # wait 5 seconds (note: time units required!)
 ```
 
 The scenario will fail if: