✨ Introduced main research page (mobile design)

ProjetProgWeb/navbar.php

@@ -0,0 +1,11 @@
+<header>
+    <nav class="navbar">
+        <h1>theses.fr</h1>
+        <form action="index.php" method="POST" class="navbar-input">
+            <input type="text" name="author" placeholder="nom auteur">
+            <button>
+                <img src="assets/search.svg" alt="search">
+            </button>
+        </form>
+    </nav>
+</header>