Start a FAQ page

* Add a HighVoltage page at `/faq`
* Link to FAQ on landing page
* Add a link to the footer of the landing page
* Override HighVoltage's `PagesController` to skip authentication and be public
* Use double quotes

Minor:
* Move styles for anchor tags from `_base` into the more specific `_header` where it used

https://trello.com/c/h9zfaC9l/386-add-an-faq