docs: link to MDN page on void elements (#8261)

Author: jamesscottbrown

site/content/docs/03-template-syntax.md

@@ -1670,7 +1670,7 @@ The only supported binding is `bind:this`, since the element type specific bindi
 
 If `this` has a nullish value, the element and its children will not be rendered.
 
-If `this` is the name of a void tag (e.g., `br`) and `<svelte:element>` has child elements, a runtime error will be thrown in development mode.
+If `this` is the name of a [void element](https://developer.mozilla.org/en-US/docs/Glossary/Void_element) (e.g., `br`) and `<svelte:element>` has child elements, a runtime error will be thrown in development mode.
 
 ```sv
 <script>