fix(i18n): Improve navigation search bar clarity

[josue-igiraneza]

Checklist:

• [x] I have read and followed the contribution guidelines.
• [x] I have read and followed the how to open a pull request guide.
• [x] My pull request targets the main branch of freeCodeCamp.
• [x] I have tested these changes either locally on my machine, or Gitpod.

Closes #59017