feat: add press kit link to footer (#531)

Author: NathanInnes

src/components/Navigation/Footer.tsx

@@ -59,6 +59,7 @@ const Footer = () => (
                                 <NavItem label="Facebook" href={links.facebook} />
                                 <NavItem label="YouTube" href={links.youtube} />
                                 <NavItem label="Twitch" href={links.twitch} />
+                                <NavItem label="Press Kit" href={links.pressKit} />
                             </NavWrapper>
                         </div>
                     </div>

src/constants/links.ts

@@ -7,4 +7,5 @@ export const links: {[name: string]: string} = {
     facebook: 'https://www.facebook.com/FlyByWireSimulations/',
     opencollective: 'https://opencollective.com/flybywire',
     docsfaq: 'https://docs.flybywiresim.com/faq',
+    pressKit: 'https://github.com/flybywiresim/branding',
 };