doc: Fix formatting of examples headers in README (#512)

This commit ensures all example subsection headers are properly
rendered by GitHub replacing non-breaking spaces (ascii code 160)
with regular spaces (ascii code 32).

Author: jcfr

README.md

@@ -179,7 +179,7 @@ jobs:
         status: "${{ job.status }}"
 ```
 
-### Action with custom hold comments
+### Action with custom hold comments
 
 ```
 name: Test
@@ -200,7 +200,7 @@ jobs:
         failComment: "action failed!"
 ```
 
-### Action no comments, set commit to "error" status and set url, description and specific name
+### Action no comments, set commit to "error" status and set url, description and specific name
 
 ```
 name: Test