Update social media icons to local assets and enhance donation message for clarity

Author: nikoscham

assets/Font_Awesome_5_brands_blogger_feascript.svg

@@ -85,7 +85,7 @@ <h1>A JavaScript Finite Element Simulation Library</h1>
       <li class="icon-link-start">
         <a href="https://blog.feascript.com/" title="FEAScript Blog">
           <img
-            src="https://upload.wikimedia.org/wikipedia/commons/8/89/Font_Awesome_5_brands_blogger.svg"
+            src="./assets/Font_Awesome_5_brands_blogger_feascript.svg"
             alt="Blog Icon"
             style="height: 20px; vertical-align: middle"
           />
@@ -94,7 +94,7 @@ <h1>A JavaScript Finite Element Simulation Library</h1>
       <li>
         <a href="https://www.youtube.com/@FEAScript" title="FEAScript YouTube">
           <img
-            src="https://upload.wikimedia.org/wikipedia/commons/8/8b/YouTube_dark_icon_%282017%29.svg"
+            src="./assets/YouTube_dark_icon_%282017%29_feascript.svg"
             alt="YouTube Icon"
             style="height: 18px; vertical-align: middle"
           />
@@ -103,7 +103,7 @@ <h1>A JavaScript Finite Element Simulation Library</h1>
       <li>
         <a href="https://github.com/FEAScript/FEAScript-core" title="FEAScript GitHub">
           <img
-            src="https://upload.wikimedia.org/wikipedia/commons/9/91/Octicons-mark-github.svg"
+            src="./assets/Octicons-mark-github_feascript.svg"
             alt="GitHub Icon"
             style="height: 20px; vertical-align: middle"
           />
@@ -144,7 +144,7 @@ <h2 id="gettingstarted"><a name="Getting Started"></a>Getting Started</h2>
         code.
       </li>
     </ul>
-
+    <br />
     <div class="highlight-container" style="margin-bottom: 1.5em">
       <p>
         <strong>Latest stable release:</strong>
@@ -155,7 +155,10 @@ <h2 id="gettingstarted"><a name="Getting Started"></a>Getting Started</h2>
           <a href="https://github.com/orgs/FEAScript/discussions/17">0.2.0</a></i
         >
         <br />
-        <strong>Support FEAScript development:</strong>
+        <strong
+          >If you find FEAScript useful, please consider supporting its development through a
+          donation:</strong
+        >
         <script src="https://liberapay.com/FEAScript/widgets/button.js"></script>
         <noscript
           ><a href="https://liberapay.com/FEAScript/donate"