Fix HTML script tag for minimal banner size (#226)

just a Quotation mark was missing there

Author: Gauravchaubey66

src/content/pages/banner.md

@@ -56,7 +56,7 @@ Link to a custom page, no close button:
 Minimal size without animations.
 
 ```html
-<script src="https://keepandroidopen.org/banner.js?size=minimal&animation=off></script>
+<script src="https://keepandroidopen.org/banner.js?size=minimal&animation=off"></script>
 ```
 <div id="my-banner-minimal"></div>
 <script src="/banner.js?size=minimal&animation=off&id=my-banner-minimal"></script>