Broken FAQ link on Stats page

[alexclifton4]

Describe the bug
The FAQ link in the header contains a relative link, so if it is clicked from the Stats page it does not work.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://spotify-dedup.com/stats
2. Click on FAQ in the top right
3. Notice nothing happens

Expected behavior
The user should be taken to the FAQ page

I tried to fix this and submit a PR, but it seems the header is not in this repo.