User Story: Feed Section

[lienebriede]

As a registered user, I want to access a "Feed" section from the navbar so that I can see shared habit stack achievements from other users and share mine.

Acceptance Criteria

• A "Feed" button is added to the navbar.
• Clicking it navigates to the Feed page.

Tasks

• Add a "Feed" button to the navbar.
• Create a Feed page UI.