Merge pull request #403 from ashawley/sync-center-layout

Sync center layout with default

Merge pull request #400 from ashawley/active-nav-underline-defect

Fix defect with underline in nav

Merge pull request #394 from ashawley/service-worker

Add initial Service Worker

Merge pull request #385 from ashawley/copyright

Update copyright to 2019

Merge pull request #379 from ashawley/drop-txtpen

Drop txtpen revert #325

Merge pull request #377 from ashawley/fix-link-tag

Fix missing bracket on link tag

Merge pull request #371 from ashawley/baseurl-favicon

Fix baseurl for Favicon and Apple icons

Merge pull request #359 from Wilfred/patch-1

Fix invalid property

This was a long lived typo : (

Merge pull request #356 from ashawley/liquid-warning

Fix build warning in index.html layout