Fix typo in main nav

Author: mabhub

src/components/Navbar.js

@@ -59,7 +59,7 @@ const Navbar = class extends React.Component {
                 Data science
               </Link>
               <Link className="navbar-item" to="/ialearning">
-                Data Managment
+                Data Management
               </Link>
               <Link className="navbar-item" to="/contact">
                 Nous contacter