feat(index.html): Use absolute image source relative to local instance

Author: Fuwn

index.html

@@ -229,7 +229,7 @@ <h2>Username</h2>
       <div class="counter">
         <img
           id="example"
-          src="https://mayu.due.moe/get/@demo"
+          src="/get/@demo"
           alt="Example counter"
           class="example-image"
         />
@@ -292,7 +292,7 @@ <h2>Username</h2>
           themeValue = themeSelect.value;
         }
 
-        image.src = `https://mayu.due.moe/get/@${inputValue}?theme=${themeValue}&padding=6`;
+        image.src = `/get/@${inputValue}?theme=${themeValue}&padding=6`;
 
         setCopyCodes();
       };