Add missing strings.yml for Jekyll search feature

[Copilot]

The Jekyll search feature references site.data.strings.search_placeholder_text and site.data.strings.search_no_results_text in the topnav template, but docs/_data/strings.yml was missing, causing empty strings to be rendered.

Changes

• Added docs/_data/strings.yml with required UI string definitions:
  • search_placeholder_text: Search...
  • search_no_results_text: No results found

Before/After

<!-- Before: Empty placeholder and no-results message -->
<input type="text" id="search-input" placeholder="">
SimpleJekyllSearch.init({ noResultsText: '', ... })

<!-- After: Proper UI text -->
<input type="text" id="search-input" placeholder="Search...">
SimpleJekyllSearch.init({ noResultsText: 'No results found', ... })

Original prompt

Please investigate why the Jekyll search feature is not working in the /docs Jekyll site. The configuration appears to be correct.

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.