minor improvements:

- page titles
- favicon
- background logo

frontend/src/routes/company/Index.svelte

@@ -63,6 +63,10 @@
     onMount(loadCompanies)
 </script>
 
+<svelte:head>
+    <title>Umbrella – {t('companies')}</title>
+</svelte:head>
+
 <fieldset>
     <legend>
         {t('companies')}