fix(docs): wrap install commands on mobile (768px breakpoint)

Same fix as go-vector: .install-box code was white-space: nowrap,
overflowing on mobile. Adds responsive override matching existing
768px breakpoint used by .usecase.

Author: molty3000

docs/index.html

@@ -77,6 +77,10 @@
     }
     .install-box .prompt { color: var(--green); font-weight: 600; }
     .install-box code { color: var(--text-primary); }
+    @media (max-width: 768px) {
+      .install-box { padding: 12px 16px; font-size: 13px; }
+      .install-box code { white-space: normal; word-break: break-all; overflow-wrap: break-word; }
+    }
 
     /* Syntax highlighting */
     .kw { color: #c084fc; }    /* purple */