Add Decode PostgreSQL to books page

Author: Daniel Gustafsson <[email protected]>
Reported-by: Ellyne Phneah <[email protected]>
Discussion: https://postgr.es/m/AL=FH5LKVp9EzTNf3u7MTA4e7UYg+BS9_0RcCXhSrWSuzPzCHA@mail.gmail.com

Author: danielgustafsson

media/img/docs/books/decode_postgres.png

@@ -11,6 +11,21 @@ <h1>Books <i class="fas fa-book"></i></h1>
     </tr>
   </thead>
     <tbody>
+      <tr>
+        <td>
+            <a href="https://decodepress.gumroad.com/l/postgresql">
+              <img src="/media/img/docs/books/decode_postgres.png"
+                   alt="Decode PostgreSQL: Understanding the World's Most Powerful Open Source Database Without Writing Code" /></a>
+        </td>
+        <td>
+           <strong>Title</strong>: Decode PostgreSQL: Understanding the World's Most Powerful Open Source Database Without Writing Code<br />
+           <strong>Author</strong>: Ellyne Phneah<br />
+           <strong>Language</strong>: English<br />
+           <strong>Current version at publication</strong>: 17<br />
+           <strong>Format</strong>: eBook<br />
+           <strong>Published</strong>: September 2025
+        </td>
+      </tr>
       <tr>
         <td>
             <a href="https://www.manning.com/books/postgresql-mistakes-and-how-to-avoid-them">