Add Forum button to hero section linking to Image.sc

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: etzm

_includes/hero.html

@@ -6,6 +6,7 @@ <h1 class="hero-headline">{{ site.data.site.hero.headline }}</h1>
         <div class="hero-cta">
             <a href="{{ site.data.site.hero.cta_primary.url }}" class="btn btn-primary" target="_blank" rel="noopener">{{ site.data.site.hero.cta_primary.label }}</a>
             <a href="{{ site.data.site.hero.cta_secondary.url }}" class="btn btn-outline">{{ site.data.site.hero.cta_secondary.label }}</a>
+            <a href="{{ site.data.site.community.forum_url }}" class="btn btn-outline" target="_blank" rel="noopener">Forum</a>
         </div>
         <div class="hero-meta">
             {% for item in site.data.site.meta %}