feat: update icon and change the directory of htmls

assets/htmls/about.html

@@ -0,0 +1,29 @@
+<center>
+    <p>
+        <img width='128' height='128' src=':/icons/app-icon.png'/>
+        <br/>
+        <!-- Application name -->
+        <span>%1</span>
+        <br/>
+        <!-- Version info -->
+        <span>%2</span>
+    </p>
+    <hr/>
+    <p>
+        <!-- Upstream author and fork author -->
+        <span>%3</span><span>:&nbsp;</span><a href='https://github.com/BLumia'>@BLumia</a>
+        <br/>
+        <span>%4</span><span>:&nbsp;</span><a href='https://github.com/yyc12345'>@yyc12345</a>
+        <br/>
+        <!-- Icon author -->
+        <span>%5</span><span>:&nbsp;</span><a href='https://github.com/Lovelyblack'>@Lovelyblack</a>
+    </p>
+    <hr/>
+    <p>
+        <!-- Built Qt version info -->
+        <span>%6</span>
+        <br/>
+        <!-- Source code -->
+        <span>%7</span><span>:&nbsp;</span><a href='https://github.com/BLumia/pineapple-pictures'>GitHub</a>
+    </p>
+</center>