NickAKhmetov/CAT-TBD Accessibility Issue Fixes

[NickAkhmetov]

Summary

• Add lang="en" to sitewide template

Design Documentation/Original Tickets

Link to any design documents, diagrams, or JIRA tickets relevant to this feature.

Testing

Describe how the feature has been tested, including both automated and manual testing strategies.

Screenshots/Video

Include screenshots or video demonstrating any significant visual or behavioral changes.

Checklist

• [ ] Code follows the project's coding standards
  • [ ] Lint checks pass locally
  • [ ] New CHANGELOG-your-feature-name-here.md is present in the root directory, describing the change(s) in full sentences.
• [ ] Unit tests covering the new feature have been added
• [ ] All existing tests pass
• [ ] Any relevant documentation in JIRA/Confluence has been updated to reflect the new feature
• [ ] Any new functionalities have appropriate analytics functionalities added

Additional Notes

Please specify any additional information or context relevant to this PR.