Finished bare-bones Hero section

- Finished bare-bones Hero section without content in both color schemes
- One image in publi/temp.jpg (for hero section, TODO: replace and rename)

TODO:
* jump-scroll
* about sections

src/pages/[lang]/index.astro

@@ -12,6 +12,6 @@ export async function getStaticPaths() {
   });
 }
 ---
-<MainLayout title={title} description={description} lang={Astro.currentLocale} themeOverride="">
+<MainLayout title={title} description={description} lang={Astro.currentLocale} themeOverride="dark">
   <Hero />
 </MainLayout>