docs: make writing guidelines shorter

Author: f-hollow

content/pages/contribution-guide/writing-content/index.md

@@ -42,7 +42,7 @@ The default Espressif author is used:
 - For posts generated by scripts, such as automatic compilations, release notes, and so on
 - For articles generated with AI
 
-In other cases, add yourself as an author. For this, do the following:
+In other cases, add yourself as an author:
 
 - Create your author entry
   - At `content/authors/<author-name>/_index.md`, create your page