Add LCM practice

src/navbar.tsx

@@ -0,0 +1,24 @@
+import Container from 'react-bootstrap/Container';
+import { NavLink } from 'react-router-dom'
+import Nav from 'react-bootstrap/Nav';
+//import NavItem from 'react-bootstrap/NavItem'
+import RBNavbar from 'react-bootstrap/Navbar';
+//import NavDropdown from 'react-bootstrap/NavDropdown';
+
+function Navbar() {
+  return (
+    <RBNavbar expand="lg" className="bg-body-tertiary" sticky="top">
+      <Container>
+        <RBNavbar.Toggle aria-controls="basic-navbar-nav" />
+        <RBNavbar.Collapse id="basic-navbar-nav">
+          <Nav className="me-auto">
+            <NavLink to="/gcf" title="Greatest Common Factor" className={({ isActive, isPending }) => "nav-link " + (isPending ? "" : isActive ? "active" : "")}>GCF</NavLink>
+            <NavLink to="/lcm" title="Least Common Multiple" className={({ isActive, isPending }) => "nav-link " + (isPending ? "" : isActive ? "active" : "")}>LCM</NavLink>
+          </Nav>
+        </RBNavbar.Collapse>
+      </Container>
+    </RBNavbar>
+  );
+}
+
+export default Navbar;