Add GitHub star button to the main page

Author: meator

src/packaging/index.md

@@ -2,8 +2,13 @@
 other pages use relative links as expected. This is because of
 https://github.com/rust-lang/mdBook/issues/2341 -->
 
+<div style="display: flex; align-items: center;">
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 # Xbps-src packaging tutorial
 
+<iframe style="margin-left: auto; color-scheme: light;" src="https://ghbtns.com/github-btn.html?user=xbps-src-tutorials&repo=xbps-src-tutorials.github.io&type=star&count=true&size=large" frameborder="0" scrolling="0" width="170" height="30" title="GitHub"></iframe>
+</div>
+
 **This tutorial is up to date as of September 29, 2024**
 
 This tutorial will guide you through packaging with `xbps-src`, either for