Fix: changed the hover color for better visibility in navbar

[TenzDelek]

Issue: the current navbar hover have matching colour theme with the background resulting in visibility issue in design.

Changes: makes the hover colour a subtle grey , differentiating the foreground and the background.

[knative-prow[bot]]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: TenzDelek Once this PR has been reviewed and has the lgtm label, please assign davidhadas for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment Approvers can cancel approval by writing /approve cancel in a comment

[netlify[bot]]

✅ Deploy Preview for knative ready!

Built without sensitive environment variables

Name	Link
🔨 Latest commit	32c6cff48ba6e303bcaa116eb403e12e9a9c63d6
🔍 Latest deploy log	https://app.netlify.com/sites/knative/deploys/6645cdf33d5c0a0007dd238a
😎 Deploy Preview	https://deploy-preview-5977--knative.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[github-actions[bot]]

This Pull Request is stale because it has been open for 90 days with no activity. It will automatically close after 30 more days of inactivity. Reopen with /reopen. Mark as fresh by adding the comment /remove-lifecycle stale.