Added .gitignore and modified the index.html added a book

.gitignore

@@ -0,0 +1 @@
+**/.DS_Store

index.html

@@ -170,6 +170,18 @@ <h2>Coding Language Books</h2>
       </td>
     </tr>
   </div>
+  <h2>Database System Books</h2>
+  <div id="databse-system-books-container">
+      <tr>
+      <td>
+        <a class="box1" target="”_blank”"><img class="poster" src="./public/BooksThumb/dbms-practical-approach.png" alt="Book Cover DBMS practical approach" />
+          <button
+            onclick="window.location.href='https://drive.google.com/uc?export=download&id=1UZ2dS2HSW2DTybO4XxisJxHHeD8vZHM0';"
+            class="mybuttonoverlap btn btn-info">
+            Download<i class="bx bx-xs bx-download" style="color: white; padding-left: 0.5em"></i></button></a>
+      </td>
+    </tr>
+  </div>
   <a href="#" id="toTopBtn" class="cd-top text-replace js-cd-top cd-top--is-visible cd-top--fade-out" data-abc="true"></a>
   <footer>
     <h3>