Fix broken links

[vzDevelopment]

This fixes:

• Link to the new FN API docs.
• Fix FN Logo homepage link - it's not going back to the home page.

As mentioned in #52.

To test:

• Click the FN API link in the side bar and it should go to the correct Swagger URL
• Click the Fn Logo when looking at an App and it should take you back to the home page