Encapsulate scripts in header and footer

Author: CptWesley

_includes/footer_custom.html

@@ -1,6 +1,8 @@
 <script>
+(function(){
     const button = document.getElementById('edit-this-page');
     const oldUrl = button.href;
     const newUrl = oldUrl.replace('/main-repo/', '/');
     button.href = newUrl;
+})();
 </script>

_includes/header_custom.html

@@ -27,6 +27,7 @@
 <a class="site-button" id="theme-toggle" style="cursor: pointer;"></a>
 
 <script>
+(function(){
     const light = 'light';
     const dark = 'dark';
     const system = 'system';
@@ -88,4 +89,5 @@
 
     button.addEventListener('click', toggleTheme);
     setTheme(loadedTheme);
+})();
 </script>