Scheme-less links (e.g. twitter.com/jeffhicks) render as broken relative links

[HeyItsGilbert]

Reported during the link/rendering review in #19.

Problem

Some links in migrated content are missing their https:// scheme, so Hugo/Goldmark treats them as site-relative paths and they 404. Confirmed examples:

• content/articles/2013-04-22-meet-the-scripting-games-judges-jeffery-hicks.md — Twitter at twitter.com/jeffhicks (bare, scheme-less)
• content/articles/2013-02-16-phillyposh-02072013-meeting-summary-and-presentation-materials.md — reference def [6]: twitter.com/jeffhicks

A malformed variant also exists elsewhere in migrated content: http:/gplus.to/jeffhicks (single slash). It's worth sweeping for both patterns.

To find candidates

# scheme-less reference defs and inline links to external hosts
grep -rnE '\]\(([a-z0-9.-]+\.(com|org|net|io)/)' content/ | grep -vE 'https?://'
grep -rnE '\]:\s*([a-z0-9.-]+\.(com|org|net|io)/)' content/ | grep -vE 'https?://'
# malformed single-slash scheme
grep -rnE 'https?:/[^/]' content/

Suggested fix

• Add the missing https:// (or http:// where appropriate) scheme.
• Repair single-slash http:/ → http://.

Acceptance

• The known examples resolve to the intended external URLs; a sweep finds no remaining scheme-less external links.