feat: add early careers to navigation (#2748)

* feat: add early careers to navigation

* Apply suggestions from code review

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: petesfrench

navigation.yaml

@@ -692,6 +692,8 @@ careers:
         url: /careers/company-culture/diversity
       - title: Sustainability
         url: /careers/company-culture/sustainability
+      - title: Early careers
+        url: /careers/early-careers
 
 company:
   cta: Get to know us

secondary-navigation.yaml

@@ -45,6 +45,20 @@ cassandra:
     - title: Docs
       path: https://canonical-charmed-cassandra.readthedocs-hosted.com/latest/
 
+careers:
+  title: Careers
+  path: /careers
+
+  children:
+    - title: Jobs
+      path: /careers/all
+    - title: Hiring process
+      path: /careers/hiring-process
+    - title: Culture
+      path: /careers/company-culture
+    - title: Early careers
+      path: /careers/early-careers
+
 data:
   title: Data
   path: /data