fix(docs): allow zooming out from initial auto-fit scale in mermaid modal

Changed panzoom contain from 'outside' to false so users can freely
zoom out beyond the auto-fit size. Also reduced minScale to 0.05 to
allow more zoom-out range.

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

Author: JusterZhu

website/src/theme/Mermaid/index.js

@@ -41,9 +41,9 @@ function MermaidRenderResult({ renderResult }) {
 
     const instance = panzoom(svgEl, {
       maxScale: 10,
-      minScale: 0.1,
+      minScale: 0.05,
       step: 0.15,
-      contain: 'outside',
+      contain: false,
       pinchAndPan: true,
     });
     instanceRef.current = instance;