DEV: make class name more unique to prevent collisions (#10)

naming a nav link "Directory" for instance collides with a core css class name

Author: weallwegot

common/header.html

@@ -15,7 +15,7 @@
  const deviceClass = `.${seg[3]}`;
  const linkTarget = seg[4] === "self" ? "" : "_blank";
  const keepOnScrollClass = seg[5] === "keep" ? ".keep" : "";
- const linkClass = `.${linkText.trim().toLowerCase().replace(/\s/gi, '-')}`;
+ const linkClass = `.${linkText.trim().toLowerCase().replace(/\s/gi, '-')}-custom-header-links`;
 
  if (!linkTarget) {
  headerLinks.push(