change some styling for index and config

Signed-off-by: Arthur Lu <learthurgo@gmail.com>

index.html

@@ -24,13 +24,14 @@
 				</div>
 			</nav>
 		</header>
-		<main class="w3-container">
-			<h2>Instances</h2>
-			<div id="instance-container">
-			</div>
-			<div class="center-div" style="text-align: center;">
-				<img id="instance-add" src="images/actions/instance/add-instance.svg" class="clickable" alt="Create New Instance" title="Create New Instance">
-			</div>
+		<main>
+			<section class="w3-container">
+				<div class="flex row nowrap" style="justify-content: space-between;">
+					<h2>Instances</h2>
+					<button type="button" id="instance-add" class="w3-button">Create New Instance</button>
+				</div>
+				<div id="instance-container" class="w3-card w3-padding"></div>
+			</section>
 		</main>
 	</body>
 </html>