Add custom icon for code-re2c card

Author: deimonn

src/assets/icons/code-re2c.png

@@ -45,7 +45,7 @@ <h2>Extensions</h2>
 
   <sl-card>
     <b slot="header">
-      <img src="/assets/icons/extension.png"/>
+      <img src="/assets/icons/code-re2c.png"/>
       <span>code-re2c</span>
     </b>
     <p>Linting and syntax highlighting for re2c</p>