Tidies up some shortTitles to fix alphabetical ordering in REST docs (#56443)

Author: subatoi

content/rest/campaigns/index.md

@@ -1,6 +1,6 @@
 ---
 title: REST API endpoints for security campaigns
-shortTitle: Security campaigns
+shortTitle: Campaigns
 intro: Use the REST API to create and manage security campaigns for your organization.
 topics:
   - API

content/rest/code-security/index.md

@@ -1,6 +1,7 @@
 ---
-title: Security settings
-intro: Use the REST API to create and manage security configurations for your organization.
+title: REST API endpoints for code security settings
+shortTitle: Code security settings
+intro: Use the REST API to create and manage code security configurations for your organization.
 topics:
   - API
 autogenerated: rest