Add external links to sub navigation menu

[evandrosaturnino]

Description

Add external links to the sub navigation menu - Needed initially to include tBTCScan external link.

• add external links to sub navigation menu
• add tbtcscan link to tbtc sub navigation menu

Type of change

• 💅 New Feature (Breaking/Non-breaking Change)
• 🐛 Bug fix (Non-breaking Change: Fixes an issue)
• 🛠️ Chore (Non-breaking Change: Doc updates, pkg upgrades, typos, etc..

Notice

• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Issue (if applicable)

closes #776

Screenshots (if applicable)

Pull Request Type

• New Feature (Breaking/Non-breaking Change)

[github-actions]

Preview uploaded to https://preview.dashboard.test.threshold.network/add-external-links-to-sub-navigation-menu/index.html.

[somaweb3]

Thanks for the tbtcscan redirect, the changes look good.

[michalsmiarowski]

Left two non-blocking comments. Let me know if we want to address them before the merge.

[github-actions]

Preview uploaded to https://preview.dashboard.test.threshold.network/add-external-links-to-sub-navigation-menu/index.html.

[michalsmiarowski]

LGTM

[github-actions]

Preview uploaded to https://preview.dashboard.test.threshold.network/add-external-links-to-sub-navigation-menu/index.html.