Move header to dedicated file
Expand header, add template tags

* Expand the header using template tags (inspired by standard WordPress headers)
* Create footer to balance elements
* Format indentation consistently (boo, formatting change mixed with logic)
Add basic styling (colors)
Add global variables

* Add /sass/partials/_variables.scss
* Define global variables, more semantic (!hss) than direct variables for color and font size
Add sandbox; implement syndication links

* Add a sandbox page for (fun) stuff that'll be integrated later
* Sandbox: Implement syndication links
* Add a few placeholder files that ended up not being used, but probably will