Social: add OG card for link previews (WhatsApp, LinkedIn, Twitter, etc.)

Generated a 1200x630 social card at static/img/og-card.png and wired
it into themeConfig.image in docusaurus.config.ts. Every page now
renders an og:image meta tag pointing at this card, so link previews
on WhatsApp / LinkedIn / Twitter / Slack etc. show a branded card
instead of nothing.

The card is dark-themed with the green accent, matching the site:
name, tagline, a row of five tech chips, and the URL. Generated from
an SVG template via Chrome headless so the output is a proper PNG at
1200x630 (WhatsApp in particular doesn't reliably render SVG OG
images). SVG template not committed; the PNG is the artefact the
site serves.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: franrob-projects

docusaurus.config.ts

@@ -56,8 +56,7 @@ const config: Config = {
   ],
 
   themeConfig: {
-    // Replace with your project's social card
-    // image: 'img/docusaurus-social-card.jpg',
+    image: 'img/og-card.png',
     colorMode: {
       defaultMode: 'dark',
       disableSwitch: true,