fix: Adjustment to header H3 of the PR-558.md.

documentation/new-notes/PR-558.md

@@ -1,4 +1,4 @@
-# New atInit Command Added
+### New atInit Command Added
 
 This pull request introduces a new IOC shell command `atInit` to EPICS Base, which allows users to schedule arbitrary commands to be executed automatically after the IOC initialization phase (`iocInit`).
 
@@ -7,7 +7,7 @@ The module allows you to write better-structured ioc shell files to include in y
 - to improve writing boot sequences,
 - to improve IOC startup flexibility and scripting capabilities.
 
-## Features
+#### Features
 
 - Define commands that run after IOC initialization completes.
 - Overwrites ```autosave``` to ensure proper configuration of the required PV.
@@ -16,7 +16,7 @@ The module allows you to write better-structured ioc shell files to include in y
   - `atInit "dbpf <PV> <VAL>"`
   - `atInit "date"`
 
-## Testing
+#### Testing
 
 - Unit tests have been added to verify:
   - Registration and execution of commands scheduled with `atInit`.